
A COLLECTION OF 



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THE MECHANICS FRIEND, 



PRINTED BY BALLANTYNE AND COMPANY 
EDINBURGH AND LONDON 




-> 



'S FRTEND; 



A COLLECTION OF 



RECEIPTS AND PRACTICAL SUGGESTIONS 



AQUARFA, 
BRONZING, 
CEMENTS, 
DRA WING, 
DYES, . 
ELECTRICITY, 
GILDING, 
GLASS- WORKING, 



RELATING TO 
GL UES, 

HOROLOGY, 

LACQUERS, 

LOCOMOTIVES, 

MAGNETISM, 

ME TAL-WORKING, 

MODELLING, 

PHOTOGRAPHY, 



PYROTECHNY, 

RAILWAYS, 

SOLDERS, 

S TEA M-E NGINE, 

TELEGRAPHY, 

TAXIDERMY, 

VARNISHES, 

WA TERPROOFING, 



MISCELLANEOUS TOOLS, INSTRUMENTS, MACHINES, AND PROCESSES 
CONNECTED WITH THE CHEMICAL AND MECHANICAL ARTS. 



WILLIAM ET^^O'^fxSrM.R.S.L., F.S.S. 

MEMBER OF THE LITERARY AND PHILOSDPHICAL SOCIETY OF MANCHESTER, ETC ETC. 



NEW YORK: 

D. VAN NOSTRAND. 

1875. 



fl*v 



7?? 




3 



PREFACE. 



The present differs in some important particulars 
from the many " receipt-books " which have preceded 
it. It is the result, not so much of individual judg- 
ment as of the action of a number of " friends in 
council,'* whose varied practical experiences have 
inspired the instructions and hints it contains. 
The articles of which the volume consists have 
already appeared in the English Mechanicy a well- 
known periodical, in whose pages lovers of science, 
practical mechanics, chemists, photographers, &c. &c., 
have for years past been in the habit of affording 
mutual help to each other. Hence almost every item 
of information in the present volume is a statement 
of a difficulty experienced by one person, and re- 
sponded to by another, who has already met and 
overcome it. This fact will stamp the book with a 
practical value in the eyes of those who know how 
much more important such individual experience is 
than any mere theory or tradition. The workman 



viii PREFACE. 



who looks here for help will know that he is listening 
to those who have been in his own circumstances, 
and who by perseverance, it may be, in spite of 
repeated failures, have at last found out the method 
they now offer to him. 

There is a large and rapidly-increasing class of 
amateurs who devote some of their leisure to working 
in the mechanical and other branches of practical 
science. These persons will, it is hoped, in this 
volume find many things to save them trouble and 
speed them on their way. Whether they want to 
skeletonize the leaf of a plant, or to construct a 
steam-propeller for a model boat ; to make a sky- 
rocket or an electric clock ; an artificial magnet or a 
photographic handkerchief, they will not look in vain. 
The tendency to the traditional in every trade renders 
it probable that, with persons of this class, many 
improved processes will originate. The amateur 
workman looks at things with a fresher eye than one 
who has come to regard the processes learned in youth 
as the finale of perfection. Discoveries sometimes 
arise from the extension of principles and methods 
that have proved successful in one department to 
other spheres of operation. Bearing this in mind, it 
is perhaps not to be regretted that so few men adopt 
as " hobby " the pursuits by which their living is 
obtained. The joiner whose evenings are given up 



PREFACE, ix 



to clockmaking, the printer whose holiday-time is 
spent in photography, are not to be discouraged as 
perverse. They bring trained intelligence to bear 
upon fresh fields, and the stoutest resister of outside 
suggestions in his trade may be the most daring 
experimenter in relation to his hobby. Both classes 
will, it is hoped, find something to suit them in the 
following pages. 

In preparing for the press the contributions of so 
many individuals, a considerable amount of revision 
and condensation has been necessary, and every 
possible care has been taken to exclude matter 
already easily accessible. 

The topics have, as far as possible, been grouped 
together according to their mutual relationship ; but 
as all such attempts at classification are in their very 
nature defective, this arrangement has been supple- 
mented by a copious alphabetical index. 



TABLE OF CONTENTS, 











PAGE 


METRIC SYSTEM ...... I 


MISCELLANEOUS TOOLS, INSTRUMENTS, AND PROCESSES 3 


CEMENTS AND GLUES 








• 79 


VARNISHES AND LACQUERS 








. 83 


SOLDERS AND SOLDERING . 








. 90 


METALS AND METAL-WORKING 








92 


STEAM ENGINE 








. 102 


RAILWAYS AND LOCOMOTIVES 








130 


FIRE-ARMS . 








. 148 


HOROLOGY .... 








150 


GLASS .... 








• 175 


WOOD-WORKING 








179 


HOUSE AND GARDEN 








184 


DRAWING AND MODELLING 






, « 


197 


PHOTOGRAPHY 








203 


MUSICAL INSTRUMENTS 








228 


TAXIDERMY . 








234 


PLANT PRESERVING 








238 



Xll 



TABLE OF CONTENTS, 





PAGE 


AQUARIA ...... 


. 240 


MISCELLANEOUS CHEMICAL PROCESSES AND COMPOSI 


- 


TIONS . . . . . . . 


. 246 


LIGHTING ...... 


. 262 


DYES . . . 


. 265 


WATERPROOFING ..... 


. 268 


GILDING AND BRONZING .... 


270 


PYROTECHNY ..... 


289 


ELECTRICITY, MAGNETISM, AND TELEGRAPHY . 


. 295 


INDEX . . . . . 


zzz 



THE MECHANICS FRIEND. 



French Weights and Measures, and their English Equi- 
valents. — The very general use of the metrical system in 
scientific investigations renders a brief statement of it indis- 
pensable. The following will be found sufficient for all ordinary 
purposes : — 



I. — ^ Weights. 

Bar (cubic metre of water) . . . = 

Myriagramme . . . . . = 

Kilogramme = 

Hectogramme . . . . . = 

Decagramme = 

Gramme = 

Decigramme = 

Centigramme = 



lbs. 

5673 
26 



English Troy Weighf. 



oz. dwts. 



3 
10 

3 
4 
6 



grams. 

8 
20 

2 

7*4 
10-34 
15*434 

1*5434 

015434 



Quadrant of meridian 

Degree centesimal 

Myriametre 

Kilometre 

Hectometre 

Decametre 

Metre 



II. — Linear Measures. 

French Foot. 
= 30784440 

= 3078444 
3078444 
3078-444 

307-8444 
== 3078444 

3-078444 



English Foot. 
32809167 
328091-67 
32809-167 
3280-9x67 
328-09167 
32*809167 
3-2809167 



WEIGHTS AND MEASURES. 







French Lines. 


English Lines. 


Decimetre 


, 


. = 44-3296 


47-2452 


Centimetre . 


, 


. = 4'43296 


4-72452 


Millimetre . 


• 


. = 0443296 
III.— Square Measures. 


0-472452 






French Square Feet. 


English Square Feet. 


Myriare 


= 


9476817-46113 


10764414-3923 


Kilare 


= 


947681 7461 13 = 


1076441-43923 


Hectare 


= 


94768'i746ii3 = 


IO7644-143923 


Decare 


= 


9476-81746113 


10764-4143923 


Are 


= 


947-681746113 = 


IO76-44143923 


Deciare 


= 


94-7681746113 = 


107-644143923 


Centiare . 


= 


9-47681746113 = 


10-7644143923 






French Square Inches. 


English Square Inches. 


Square decimetre 


= 13-646617 = 


15500765 






French Square Lines. 


English Square Lines. 


Square centimetre 


19-651 134 


22-321088 


Square millimetre 


= 0-19651134 = 


0-22321088 






IV. — Solid Measures. 





The Stere, being a cubic metre, it follows that the Decastere is 
equal to the Myrialitre. 
Stere = Kilolitre. 

Decistere = Hectolitre. 



V. — Measures of Capacity. 



Myrialitre 

Kilolitre (or cubic metre) 

Hectolitre 



French Cubic Feet. 
= 291-738519 
= 29-1738519 
= 2-91738519 



English Cubic Feet. 
353-1714695 
35-31714695 
3-531714695 



Decalitre 

Litre (cubic decimetre) 

Decilitre 



French Cubic Inches, 
= 504*124160 
= 50-412416 
=s: 5-0412416 



English Cubic Inches. 
= 610-2802806 
= 61*02802806 
= 6-102802806 



Centilitre 



French Cubic Lines. 
= 871-126926 



English Cubic Lines. 
1054-5643249 



MISCELLANEOUS TOOLS, ETC. 



Hand Drilling-Machine. — The following machine answers 




Fig. I. 



for all work, and is said to be nearly equal to steam power. 
The machine is made by E. & H. Widdall, 
of Beverley, Yorkshire, i is a small hand- 
wheel ; 2, a pair of bevel- wheels ; 3 is a 
stationary collar for pressure-screw ; 4, the 
shding-racks for lowering the drill ; 5, 
centre of drill bolted to shaft. Fig. 2 is an 
end view of small wheel. 

Cork-Boring. — There are three sorts of 
tools for boring cork : the French (Dan- 
ger's), a sharp-edged steel cylinder, fixed 
in a handle, like a bradawl, with the cylin- 
der partly cut away, to get the cut piece 
out. Mohr's way is to use a tin tube, with 
a milled rim at the handle end, and the 
pieces of cork push each other out at the 
top, as in a punch. The objection to this 
(the cheapest method) is the welt, which can hardly be 




MISCELLANEOUS TOOLS, 



avoided in tin tubes. Griffin prefers a brass tube filed to an 
edge. All these tools should be oiled, and turned round 
while cutting, or they will not make a clean cut ; when the tool 
is nearly through, a piece of cork should be placed at the 
back of the piece you are cutting. The pieces cut out are 
uninjured, and will do for corking small bottles. 




Rose-Bit for Lathe. — This rose-bit may be used in the 

lathe or drilling-ma- 
chine. As a counter- 
sink it works well. 
The nose is formed 
by fihng away to a little below the centre, as shown. 

Renovating Files. — The file is to be first cleansed from all 
foreign matter, and then dipped in i part of nitric acid, 3 parts 
of sulphuric acid, and 7 parts of water, the time of immersion 
will be according to the extent the file has been worn, and the 
fineness of the teeth, varying from five seconds to five minutes ; 
on taking it out of the mixture, M-ash in water, then dip in 
milk of lime, and then wash off the lime, dry by a gentle heat 
and rub over equal parts of olive oil and turpentine, and finally 
brush over with powdered coke. It is stated that a new file is 
improved by a few seconds' immersion, and also that rasps may 
be renovated in the same way. 

To Draw Spirals. — A simple method of drawing spirals is : 

AA is a piece of wood of any length, fitted near one end 

with a pencil B ; CC is a string fixed at either end of the 

wood, and passing 
once round the roller 
D ; E is placed at 
the centre, from 
which the spiral is 
to be described ; F 
is an extra point 
to prevent turning 
B round. As AA is 

turned round the roller D, the pencil will be moved towards 
or away from it, and so a spiral will be described, the pitch 
of which may be altered by varying the diameter of the 
roller D. 



n 












D 












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— 1 



V 



E r 



INSTRUMENTS, AND PROCESSES, 



Quickening Curves. — Spirals, or quickening curves, as they 
are called, are made as follows : — 

Draw a straight line of any length ; divide this line into any 
number of equal parts, as shown in cut. Next divide one of 
these parts into halves, as at 

o ; now divide with the com- ^^ ^---^ 

passes (placing one foot upon 

o), strike the semicircle i 2. 

Now place the compasses , 1 1 1 f ^ ^ ] 1 I 

upon I, extending them to 53 \ \\} ^'^r ^ ^ S3 

2, and strike the semicircle 

2 3, but on the opposite side """-^ ^'''' 

of the line from the other 

semicircle. Now return and place the foot of the compasses 
on o, extending them to 3, and upon the opposite side, and 
again strike the semicircle 3 4. Now return again to i and 
so on, alternately placing the compasses on o and i, striking 
the curve on alternate sides of the line. 




Measuring Heights of Towers, &c. — Various modes are in 
operation, but the following will be found simple and practical : 

Choose that side of the tower around which the ground is 
most level. Should an entirely level plain not be obtainable, 
allowance must be e 

made for the in- 
equalities of the 
surface. 

At some distance 
from the tower place 
level on the ground 
a small pocket mir- 
ror, C, and recede 
backwards from it 
until the top of the 
tower E is seen 
reflected in the 
centre of the mir- 
ror. Then, as experimenter's height BA is to his distance 
from mirror C, so is the distance CD to height of tower. 

If, instead of a mirror, a trough of mercury, or even a pool 
of water, be employed for the reflection, the height of the 




MISCELLANEOUS TOOLS, 



tower may be correctly ascertained, provided the base of it and 
the medium of reflection be on the same level. Should it not 
be possible to get a level base, the difficulty is got over when 
the relative heights of the tower base and the water or mercury 
are known, such difference having only to be added or subtracted 
when the water or mercury is below or above the tower's base, 
as the case may be. 

Another method is this : Measure out the base line AB, 

200 feet long, then 
erect a sliding staff, 
similar to the sketch 
at C, one-twentieth 
of the length of the 
base line from B, 
which will be ten 
feet. Then site his 
staff hne BD in a 
direct line with E, 
by raising or lower- 
ing the top part of 




the staff, as the 



case may be. Hav- 



200-Fect 

ing made the other end of the line fast at B once set, multiply 

the length of BD 
by 20 — that is, the 
number of times 
the base line is 
divided into, which 
will give the exact 
length of the hypo- 
thenuse. Then the 
square root of the 
difference of the 
squares of the hypo- 
thenuse and the 
base is the height 
of the perpendicu- 
lar. The sketch F 
of the sliding staff 
will explain itself. 
Distances : How to Ascertain. — The following plan, or 




INSTRUMENTS, AND PROCESSES. 




modification of other plans, in use by architects and others, 
will be found simple in application: — 

First obtain a wooden tooth-powder box of the size shown 
by the circle, find the centre by a pair of compasses ; then 
draw the line A a lit- 
tle below the centre 
□, as shown. Next 
mark on the line 
AB at an angle of 
22^°, as shown. 
Next get two slips 
of silvered looking- 
glass of good qual- 
ity, but on thin 
glass of the respec- 
tive sizes, B and C 
D, and nearly as 
deep as the box 
shown on section. 
Fix the piece AB 

by small blocks of wood glued or cemented on each side, 
and take care to have them as upright as possible. 

It will be perceived the glass AB is to be permanently fixed 
at the angle shown. Then take the other piece CD, and cut 
a slight notch in the inner rim of the box so as to serve for a 
stay, and also as a centre for this to turn upon A at the back 
of this glass. Cement a thick piece of shoe-sole leather, about 
■I in. square, with a hole bored entirely through. In the side 
of the box opposite this, make a corresponding hole, and insert 
a screw which will embrace the leather at the back of the glass. 
The whole object of this is to adjust the glasses truly, as the 
angle before given cannot be got sufficiently accurate without 
subsequent adjustment. * 

Having thus fixed your glasses, cut two gaps entirely down the 
box, as shown at RV, and in a line with R, and perpendicular 
to A □, cut a smaller slit F for the eyehole. Now scrape 
away neatly the silver from the upper portion of AB down to 
half its depth, as shown in section, and sufficiently wide to 
admit of seeing each side of the hole R, when the eye is 
applied to the slit. Blacken those portions of the glass not 
visible from the eyehole, as they only tend to procure false 



^^ 








. \ 








1 \ 








t 


\ 






1 

1 








1 
1 








1 


\ 




/E 


I 




\ 


^ / 


k— 


F,2r 


-X 








f" 


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f 
M 



8 MISCELLANEOUS TOOLS, 

images, about two thirds of C, and may also be blackened from 
D to about F. 

The instrument now merely requires to have the lid put on, 
premising that you have first blackened every portion of the 
inside of it as well as the box. 

To adjust the instrument proceed as follows : — 
Get three sticks or laths about 3 feet long, find a tolerably 

level piece of ground, put 
in A, then with a tape or 
rod measure 24 ft., and put 
in B ; then from B with 40 
ft. on the tape, and using B 
as a centre for the ring to 
work upon, strike the arc 
EF on the ground. Again 
return to A, and with a 
radius of 32 ft. cut the former 
arc with another arc GH, and 
at the front of intersection 
put in your third stick. You have now a true square to work 
upon. 

Now measure off on the line AC 24 ft., and replace the stake 
C at that distance. You will then have a square whose sides 
are equal, and whose angle is a right angle. 

Place the instrument on the stick B, and look through the 
upper part of the glass AB, so as to see the stake A. Next 
turn the screw O more or less until the stake C is just in a line 
with the stake A, the one seen by direct vision, the other by 
double reflection. Your instrument is now adjusted. Then 
glue similar blocks of wood on each side to retain it in place, 
as in the case of AB. 

To use it, proceed as follows : — 

For vertical heights, ascertain the height of your own eye, 
and mark upon the building or spire this height, either as 
a line or a white chalk dot, walk backwards, still looking 
directly through the instrument until you see its summit, or 
any part you wish to measure, brought down on the said dot 
by reflection. You have only then to measure the distance of 
your own feet to the base of the spire, and add the height of 
your eye to it, and you have the perpendicular height you 
require. 



INSTRUMENTS, AND PROCESSES, 



For horizontal distances, say a tree C, on the opposite 
side C of the river on which you are standing, fix a 
square or cross ^^ .^^a^*^ ^ 

a staff in the direc- / i 

tion of the square / \ 

at B ; then, with / I 

your hand, move ^' I 

backwards, looking °-"- ^ " ° '--' 

at A □ in a direct line until you see the reflected image of C 
corresponding with A [U. Then measure the distance AB, 
and this is equal to CA. 

This instrument is, of course, held horizontally for the latter, 
and edgeways^ or vertically, for perpendiculars. 

Sharpening Edge Tools. — The simplest mode of sharpening 
an edge tool is to place the cutting part in water containing 
i-20th of its weight of sulphuric or muriatic acid; after allow- 
ing it to remain there for half an hour, wipe it gently with a 
piece of soft rag, and in a few hours set in on an ordinary 
strop. This method, not generally known, is by no means 
new : the effect of the acid is to supply the place of the 
oilstone, but uniformly corroding the entire surface, so that 
nothing but a good polish is afterwards needed. 

To Harden AxlfeS. — To harden pattern axles with the 
prussiate of potash of commerce, make the work red hot, then 
put on plenty of potash, and plunge in water ; or you may get 
some burnt leather or bone-dust. You can put a lot of axles 
into a wrought-iron box ; put the bone-dust or leather-cinders 
in, ram down well, put some clay over the top, build a brick 
fire round the box for about three hours, then pull out, and 
rinse in cold water ; this is the case-hardening process : you 
will find potash the quickest way. 

To Temper Drills and Taps. — Heat them first to a blood- 
red, and then quench (this gives them extreme hardness, as 
well as brittleness), then, when dry, pour oil on them, and hold 
them in the fire, fixed in a piece of iron, till the oil blazes off, 
withdrawing very frequently to watch the process. This leaves 
a hardness that the file will just touch. 



lO 



MISCELLANEOUS TOOLS, 



Protracting T -Square. — The following sketch of a pro- 
tracting 7 -square will be found useful to many : — 

A and B are the ordinary blades, and fixed stock. C is a 

stock moving as 
usual on the clamp 
screw-pin D. Into 
the inner face of 
this stock there is 
a semicircle of 
planetree (3^ inches 
radius), indented, 
which is divided 
into degrees, and 
figured from o at 
EE' to 90°. There 
are spaces cut 
through the fixed 
stock at FF' ; these 
are sloped to the 
centre, and laid 
with planetree, on 
which lines are 
drawn for reading 
off the degrees on 
the semicircle. G 
G are spaces in the 
semicircle, cut out 
for the fingers. It 
is useful for laying 
down or reading off 
angular lines, draw- 
ing polygons with 
any number of 
sides, shading at 
various angles in 
one or two direc- 
tions. 




To Temper Steel on one Edge.— Red-hot lead is an 
excellent thing in which to heat any long plate of steel that 
requires hardening only on one edge, for it need not be heated 



INSTRUMENTS, AND PROCESSES. 



II. 



in any other part but that which is required hard, and it will 
then keep straight in hardening ; at least it will keep very 
much truer than if it were heated in the midst of the ignited 
fuel of the fire. 

Fire-Fan. — This fan may be applied to any ordinary fire- 
grate, and it is almost impossible to imagine its power. A 
welding heat on 
inch iron in a com- 
mon fire-grate may 
be obtained by its 
means. 

The sides are 
formed of two pieces 
of sheet iron, the 
bottom of wood, 
length I ft. 3 in. ; 
the nose may be 
made 6 in. long, 
breadth 2 in. ; 
height 6|^ in. A 
is a wheel turning 
on a loose spindle, 
with lock-nuts for 
the end, to make a 
centre for the fan- 
spindle ; B is a 
sheet-brass pedestal 
moving on a pin, 
with a spring at the 




bottom to keep the belts in tension ; C is a bit of iron, with 
three arms riveted on to the side — the centre takes the spindle 
H ; D is a riveted arm to admit a large hole being made in 
the side, and to take a set screw for the other end of the fan- 
spindle ; E the fan ; FGI are wheels to increase the revolu- 
tions of the fan. 

Hardening and Tempering Tools and Weapons. — The 

colour and temperature required in hardening the above-men- 
tioned articles are as follows : For very soft temper, 630° 
Fah., colour greenish blue; pale blue, 610° Fah., for saws, 
the teeth of which are set with pliers ; blue, 590° Fah., for 



12 MISCELLANEOUS TOOLS, 



large saws; dark blue, 570° Fah., for small fine saws; dark 
purple, 550° Fah., for soft swords and watch-springs; light 
purple, 530° Fah., for ordinary swords and watch-springs; 
very pale purple, 520° Fah., for table-knives ; brown yellow, 
500° Fah., for adzes and plain irons ; clay yellow, 490® Fah., 
for chisels and shears ; dark straw, 470° Fah., for penknives ; 
dark yellow, 470° Fah., for razors, &:c. ; pale straw, 430° Fah., 
for lancets, &c. 

On Grindstones. — Discard every contrivance for fixing 
tools on the grindstone ; they are one and all eminently un- 
practical. A grindstone will not do nice work unless it is kept 
true, and fixing the tool against it will of course wear it away 
unevenly. Tools should always be traversed across the face of 
the stone, and when a flat surface is to be ground by a circular 
stone, it is clear that this traverse must not be exactly straight 
across it, or the bevel will be hollow. A very slight hollow is 
perhaps rather an advantage than otherwise in such tools as 
chisels and plane-irons for wood ; but there are numerous 
cases where the face should be ground as flat as possible. 
This, as just stated, cannot be accomplished by keeping the 
tool fixed against the stone. Turning-gouges, again, must be 
continually swept round in a semicircle on the stone if the 
proper form is to be obtained ; and, whatever the tool may be, 
it should be continually traversed if the figure of the stone is 
to be preserved, which is a matter of the first importance 
where accuracy in the angles of the edges is aimed at. It is 
true that some workmen have a knack of producing wonderful 
edges on stones that run like eccentrics ; but this is a rare 
gift, and the bad state of the stones in many large workshops 
has much to answer for in the very indifferent character of the 
metal-turning to be found in them. Where all run to one 
stone, few take any care of it, and it becomes almost a 
practical impossibility to grind up a slide-rest tool with 
anything like the accuracy required for first-class toolwork. 
Regular grinders, however, know the value of a true stone, and 
are very careful in keeping them so. A true-running stone 
with a good face will make the workman independent of any 
rests and holders beyond his own arms and hands. It is true 
that goniostats are used for very fine and delicate tools where 
extreme accuracy of form is essential ; but these are generally 



INSTRUMENTS, AND PROCESSES, 



13 



ground on laps running horizontally and presenting a plane 
grinding surface. 

For amateurs' use nothing is better than a treadle grind- 
stone about 20 in. or 24 in. in diameter ; and if the tools are 
always traversed on it, and it is never allowed to lie in — or 
even over — water, it may be reduced 2 in. or 3 in. diameter 
by honest work, before it requires turning up again ; and the 
operator will find, that when he has accustomed himself to 
grind true by hand alone, he will seldom want even a rest, 
and would certainly never think of spoiling his stone by using 
such an awkward and unpractical contrivance as a fixed 
holder. 



Saw-Benches. — The following plan of a saw- bench will 
suit any possessor of a lathe. The box ABC rests on the bed 
of the lathe, and is kept 
in position by the tenon 
D fitting the lathe-bed, 
and fastened by the nut 
and screw EF. The plat- 
form G is hinged at the 
back to C, and in front is 
fixed by the three tenons 
of A — shown by dotted 
lines — and the hook H. 
I is the guide for the wood 
while being sawn, and 
which is always retained 
parallel to the saw by the 
parallel movement JK ; 
it is secured by the nut 

M working in the slot N. The circular saw works through 
the groove O. This is a very simple and cheap method of 
mounting a circular saw ; but a vertical machine is more 
convenient, as the friction is less. 

The top plate should be about 18 in. long by 12 in. broad, 
the spindle about 1 8 in. long by 3 J in. thick ; the small 
pulley 3 in. large, wheel about 30 in. in diameter and weighing 
about 56 lbs. You can determine the height of the bench by 
the wheel, which should work freely. 

A is the edge of the iron plate. 




B and C the centre 



u 



MISCELLANEOUS TOOLS, 



screws for the spindle to run on, with nuts to lock the 

screws tight ; the sockets can be of cast iron for cheapness, and 

I must be screwed 

on the plate from 
front, which 




the 

must be counter- 
sunk. D is one of 
the sockets with the 
two screws. E and 
F are the nut and 
centre screw ; the 
point must be of 
hard steel. G is 
the saw and spin- 
dle, which should 
be made of iron, 
with the ends drill- 
ed out cone shape 
to fit the screws. 
H is the iron plate 
with the slot for 
the saw to run in, 
which must be 
3-i6ths of an inch 
thick, and firmly 
screwed to the 
bench. I is the 
guide made of wood 
9 in. long, with 
even face. J is 
one of the thumb- 



screws with which to fasten the guide |^-in. screw. 

Fret-Saws. — i. The following is run at a speed of from 
300 to 500 cuts per minute, and the length of stroke of the 
saw is regulated, as will be seen in the drawing. When circles 
are required to be cut, adjust a clamp, with centre pin, to 
the saw-table, and set it to the required radius. 

A, disc, with adjustable crank-pin for regulating the throw 
or length of cut. B, saw-table on a pivot C, and fixed by 
thumb-screw D. E, saw held in screw jaws. F, slide carrying 



INSTRUMENTS, AND PROCESSES, 



15 



the elbow lever, and fixed by a set screw behind. GG, 
grooved pulleys. H, stretching band of crinoline steel, kept 
in tension by the 
shde F. 

2. This fret-and- 
scroU saw is con- 
structed on the fol- 
lowing principle : — 

A is the driving 
shaft which carries 
a fly-wheel B, a 
fast-and-loose pul- 
ley CD, and on the 
end of the same 

shaft B is a disc crank E. F is a connecting rod which 
communicates the motion to a slide-block G. At each 
end of the block G 




r I G.I 



r I G . a 



is fixed a rope H 
and I, which trans- 
mit the action to 
two other slide- 
blocks K and L, 
between which the 
saw-blade is fixed. 
MNOP are four 
guide pulleys for 
the ropes. Q is a 
hand-wheel keyed 
on a lifting screw 
R, which screw goes 
through a nut on 
which the pulley P 
is bolted fast ; by 
this contrivance the 
saw-blade is tight- 
ened or slackened. 
S is a pin on which 
the table T is centred ; on its bottom side is fastened a 
segment U, to change it to any angle required. V is the belt 
guard. 

3. A vibrating fret- saw. Fig. i is a side view of the in- 




i6 



MISCELLANEOUS TOOLS. 



ternal arrangement of the working parts. 



PIC 1 



A is a flexible piece 
of wood strong enough 
to keep the saw B 
tight, lancewood or 
ash would do ; it 
must be firmly fixed 
by the thick end to 
the frame ; B is a 
fine saw ; C is the 
table-top, made of 
I J- in. birch, with a 
small hole in it for 
the saw to work 
through ; DD are two 
V-faced guide brack- 
ets screwed to under- 
side table and hav- 
ing a corresponding 
guide-piece, working 
betwixt them, to the 
top end of which is 
attached the saw, and 
the bottom end the 
rod, connecting it to 
a crank on the face 
of wheel E. It may 
be made with slot to 
alter the stroke to 
length of saw used. 

F is the driving wheel, worked by a crank with rod G and 

pedal H. Fig. 2 is a frame. 

Brazing Band-Saws. — In fig. i, G, a large cast-iron cramp 
to hold the saw while brazing it, is 3 ft. 6 in. long, a foot 
deep, and 3 in. wide. It is made hollow to allow the bolts 
AAAA to pass through the surface P. There is an open side 
left to get over this difficulty. M is the foot for resting on the 
bench ; TT are two bolts for holding it to the bench. O is a 
recess planed in the surface, of \ in. wide, 3y^ in. deep, for lay- 
ing the saw in, so that it just comes level with the surface. 
PK represents a vacancy for the tongs ; it should be made 




INSTRUMENTS, AND PROCESSES. 



17 




just low enough to admit ^-in. square iron to pass nicely 

between the saw Y 

and the bottom of 

the recess A. You 

must place the open 

side of each iron 

cramp opposite to the 

way in which you are 

standing. That will 

then bring the recess 

O close to you, when, 

placing the saw Y on 

the cast-iron cramp, 

you will have the teeth towards you, and the blank part of the 

saw will rest against the shoulder of the recess O. You can 

let it lie on the ground when the bolt- cramp AAA AAA has 

got hold of the saw Y. The tongs used require to be 7^-in. 

square iron, and to come close together. A second pair of 

tongs are also required ; they must fit nice and close, and must 

be 7 J in. wide and \ in. thick ; they are for laying hold of the 

joint after the hot tongs to keep it well together, and also to 

cool it. When commencing to braze, file | of an inch off each 

end of the brass, and taper it down to nothing. After that, 

bring the filed ends over the vacancy K, one end over the 

other, put some spelter and borax in between, and then screw 

the saw Y down with bolt-cramps AAAAAA. Now everything^ 

is ready for brazing, get 



your tongs a white heat, 
put them over the joint, 
open, just to see how the 
brass is going on ; when 
the blue flare rises, the 
brass has melted, and get 
someone to put the second 
pair of tongs on, when 
you can take the others 
away. Then loosen the 
bolts, cramp the joint from 
over the vacancy, and 

bring it farther up the recess O. Now it must be screwed 
down tight, and filed down to a uniform thickness, and you 

B 




i8 



MISCELLANEOUS TOOLS, 



will find a good strong joint ; smooth, file, and emery the 
joint, so that it will slip through the wood. 

Fig. 2. — A side view of one of the iron cramps. The dog 
Q is hollowed out in the centre, just leaving each end a little 
thicker. O is a fly-nut, H a bolt to pass through the surface 
of cast-iron cramp. Q is J in. wide, 3 in. long. 

Fig. 3 shows the end of cast-iron cramp, and how the taper 
can be filed at G. By screwing the bolts on to the saw you 
can hold it tight while you file it, which you will find a great 
advantage. In the plan, O is merely the file. 

Sawing-Machine. — The saw-frame ABCD has a central 
wooden rod EF, and a saw-blade G and H on each side, which 
are stretched by nuts and screws at ABCD in the usual way. 
The saws are guided perpendicularly by the fixed rods IJKL ; 

these pass through holes 
in the cross heads of the 
saw-frame AB and CD. 
The saw-frame is suspen- 
ded from the steel bow- 
spring M, attached to the 
column N erected at the 
back of the bench, and 
which serves to support 
O and P, in which the 
upper guide - rods are 
fitted ; the lower end of 
the saw-frame is con- 
nected by the hook Q 
with the treadle R. 

For straight cuts a 
wide saw H is used, 
and the wood is guided 
against the square fence 
S, which overlaps the 
front edge of the bench, 
and is fixed by the bind- 
ing screw T passing 
through a groove in the fence S. For circular pieces a narrow 
saw G is employed, and an adjustable centre point U, fast- 
ened by the nut V, and working in the stationary bar P, serves 
as an axis of motion for the piece of wood to be tuc. 




INSTRUMENTS, AND PROCESSES, 



19 



In order to have the bench unobstructed, so that large pieces 
may be sawn, the guide-rods IJKL, upon which the saw-frame 
works, are discontinuous, the lower pair only reach from the 
under-surface of the work-bench to WX ; while the upper pair 
are fixed to the two cross pieces O and P attached to the 
column N. 

The saws are kept steady by running in the saw-kerfs Y 
and Z, in the lower rail P of the guide-frame. The saw H is 
represented cutting a straight plank, and the saw G a circular 
piece. 

Magnetic Lock. — This, which is known as "Nobody's 
lock,'' is without keyhole, with changeable key, and is useless 
to all but the owner. It should be made of brass, or some 
non-magnetic metal (the harder the better) ; the four circular 
metallic pieces, having the adjustable magnets centred rather 
tightly on them, are suspended on pivots, which allow of rota- 
tion with sufficient ease, and have each a groove (as seen) 
nearly to the centre, to admit the four prongs of the bolt (in 
unlocking), and the whole nicely balanced. There being no 
springs, and the bolt only required to slide easily, the handle 
must be allowed to turn in its centre when the force used would 
exceed what is necessary for the sliding of the bolt. This is 
necessary to pre- 
vent injury to the ^^^^ ^^^ 
pivots of four cir- 
cular pieces. These 
details, and some 
others, are not 
shown, as they will 
be readily under- 
stood. In the il- 
lustration, however, 
the hole is dotted 
as square for the 
sake of greater sim- 
plicity. 

Lock shown com- 
plete, and the small 
handle ready to be turned, for withdrawing the bolt when the 
key (as set) is applied. 




20 



MISCELLANEOUS TOOLS, 




Key shown disarranged in a manner suitable for the conser- 
vation of magnetism, and being so applied to the lock (after 
the bolt is protruded by means of the handle) produces a like 
arrangement in the lock and the effect of locking. 

Lock with front 
^^^^ ^^^ ^ plate removed to 

exhibit the interior 
mechanism, where 
11 the key, being sup- 
posed to be ad- 
I justed over the right- 
hand end, has rotat- 
ed the magnets to 
the proper position, 
enabling the bolt to 
be withdrawn by 
turning the handle. 
Key shown ready 
set by owner to turn 
over upon its proper 
place on the lock, so as to cause the rotation of magnets as 
required to enable the bolt to be withdrawn. In the owner's 
memory the key w^ould be set thus : 4|-, 3^^, 8^, \\, 

Improved Screw-Driver for large 
Screws. — This tool possesses very 
great advantages over the common 
ones, in consequence of its being 
worked by a lever, and having a re- 
volving top. It is especially suitable 
for wheelwrights, railway-carriage build- 
ers, roof-makers, and will turn out twice 
as much work as the old ones. The 
following is a description : A is the 
point of the tool ; B is the lever, which 
can be made to fold up (when not in 
use) at the joint, as shown in the cut. 
The dotted lines near the joint are the 
four squares upon which the lever fits, 
and while in this position, you draw it to you, then lift it up 
clear of 4;he square part, and on to another, and so on. C the 




INSTRUMENTS, AND PROCESSES. 



21 



head, is the same as a common brace-head, which you keep to 
your shoulder. The head should be made of wood, and the- 
other part of steel. 

Improved Hand-Press. — Below is an adaptation for 




stronger work of 
By it you may 
punch holes \hy \ 
thick and larger, 
by simply pressing 
the lever down. In 
I is a side 



the presses for stamping on paper. 



fig 



view, fig. 2 a 
front view, and fig. 
3 section showing 
the working parts. 
A is the body ; B, 
eccentric lever ; C, 
steel pin ; D, steel 
spindle at top ; E, 
punch ; F, releaser; 
G, bed for punch ; 
HH, two set pins 
for same ; I, weight 
if required ; J, 




22 



MISCELLANEOUS TOOLS, 



lever ; K, peg to fit groove ; L, to keep spindle steady ; 
M, powerful spring to lift spindle up and release iron of the 
parallel nipple or punch. This compact little press would 




be very useful to many to whom a large one would be too 
cumbersome for light work. 

Cleaning Lenses. — Neither wash-leather nor silk will answer 
after being handled. A roll of soft blotting paper put in a case 
to keep the hands from it is the best ; velvet is also very good. 



INSTRUMENTS, AND PROCESSES, 



23 



Stud-Box and Wrench. — A capital stud-box with wrench 
can be made on tha accompanying plan. 




Alloy for Journal-Boxes. — The following alloy has been 
found to answer excellently for journal-boxes : 4 lbs. antimony, 
1 2 lbs. of tin, and 1 2 lbs. of copper. Having melted the copper, 
add the tin and afterwards the antimony. It should, after 
having been run into ingots, be cast in the form required for 
the box. 

Leakage in Smoke-Bex. — Insert in the end of tube a drift 
4 in. or 5 in. long, turned to fit the tube, slightly tapered and 
hardened : two or three sharp blows on this will suffice ; then 
run round with small caulking tool. If a bad leak in fire-box 
end, better take out tube as follows : Remove ferrule, chip off 
end of tube level with plate in fire-box, then with a drift 
(turned with a shoulder a little less than outside diameter of 
tube) drive it out from fire-box end, remove slate and scale, 
anneal ends, and replace (end to project in fire-box about \ in.), 
then drift as above. The ferrule, if not too thin, may be 
drawn a little larger, or replaced by a new one. If properly 
forged it will require no turning. Having driven the ferrule 
home, the end of tube may be riveted over to the plate ; ferrules 
are unnecessary at smoke-box end. A dolly, or piece of iron to 



24 



MISCELLANEOUS TOOLS, 



hold on drifts, long enough to clear fire and smoke box doors, is 
necessary. 

An Adjusting Carrier.— Here is a sketch of an adjusting 

carrier contrived 
by a workman in 
the employ of 
Messrs Holtzapffel. 
It is capable of 
holding anything 
from J in. up to i in. 
diameter. 

AAA. is the front 
view, B the edge ; 
they are made either 
in gun-metal, iron, 
or steel ; CCC to 
the dotted lines are 
one and the same 
pieces ; DDDD 
are separate pieces 
fitted to CCC at the 
bottom by screws 
EE, and at the top 
by screws FFF, 
which fit into a re- 
volving steel nut 
GGG, the faces of 
the screws binding 
upon the faces of 
I the nuts and the 
faces of DDDD, at 
^ one and the same 
time, just sufficient- 
ly tight to allow 
of the nuts revolving uniformly, carriering the binding or 
clamping screws HH with it, the head of H' clamping the 
smaller diameter J and the end H^ By this arrangement, 
it will be observed, that anything from \ in. to i in. dia- 
meter may be clamped without much loss of time in adjusting 
the binding or clamping screw II H upon the material 




INSTRUMENTS, AND PROCESSES. 



25 



by turning round H into H% the position of, and vice 
versa. 



Matrices for the Paper Pro- 
cess of Stereotyping. — The fol- 
lowing is the process for making 
the mould for casting stereo- 
plates by paper : Take a sheet 
of tissue paper, and having laid 
it on a perfectly even surface, 
paste on to it a soft piece of 
printing paper, pressing it evenly 
on to the tissue. Then lay the 
paper on the type form (which 
must be oiled), cover it with a 
damp rag, and beat the paper 
in evenly with a stiff brush ; 
then paste a piece of blotting, 
and repeat the beating-in ; then 
in a similar manner paste about 
these more pieces of tough 
paper, and back up with car- 
tridge paper. Dry the whole 
with a moderate heat, under 
slight pressure. When it is 
dried, brush it well over with 
either French chalk or black- 
lead, and the matrix will be 
ready for use. 



New Style of Pin. — The phrase " pin-money '' is to us of 
modern days a meaningless term, but if we go back to the 
time when the expression originated w^e find it had a painful 
significance, for prior to the introduction of the machinery for 
their manufacture a pin made by hand was in value a synonym 
for a penny. Ex- 
travagance in the 
use of pins at the 
present day is in- 
credible. The annexed engraving shows a new pin, which 
will remain in position when once placed, and not injure 





26 



MISCELLANEOUS TOOLS, 



the fabric. The improvement is in forming the shank with 
one or more swells or enlargements, beginning at or near the 
point, and terminating in square or bevelled shoulders ; or if 
designed to be permanently placed, as in fastening papers 
together, the expanded portion is provided with barbed points, 
so that if once inserted it cannot be withdrawn. 

French and English Nails compared. — A writer, assert- 
ing the superiority of French over English nails, says : 

"The fault of the Eng- 
being 




their 



lish nails is 

made in the shape of a 
wedge, which detracts from 
their holding power and 
makes them more likely 
to split the wood. The 
French nails are the 
same thickness all the way 
down, and have a sharp 
point, which is an im- 
provement that the Eng- 
lish makers seem to think 
quite unnecessary. The 
French nails are made of 
wire, they are less brittle 
than the English, and can 
be used over and over 
again without breaking. 
French nails have another 
great advantage, which is 
this, when an English 
nail is drawn out of its hole 
to a certain extent, it (owing to its wedge shape) loses all 
power of holding, whereas the French nail holds to the last." 

Drilling-Machines. — Of late years much of the harder part of 
mining, excavating, &c., is performed by machinery; a descrip- 
tion, therefore, of the principal instruments in use for that 
purpose will not be without interest to our readers. First we 
have the drilling-machine patented by Mr Newton. The 
invention relates to machines in which the working parts and 



bed are attached to an 



^ht. The feeding of the drill is 



INSTRUMENTS, AND PROCESSES, 27 

produced by a weight applied directly to the drill-stock, regu- 
lated by an adjustable counterpoise connected to the drill- stock 
by a system of levers, which also raise the stock and drill 
above the work, to permit of the adjustment and removal of 
the work from the drilling bed ; and it is in this counterpoise 
and system of levers and their connections that the first part 
of the invention lies. The second part of the invention con- 
sists of a bracket attachment, which, with the bearings in 
which the drill-stock works, are all cast in one piece and 
bolted to the standard. The third part consists in furnish- 
ing the adjustable bed-plate with a fixed jaw and a sliding jaw 
which works in fixed guides on the bed, and is adjustable by 
a screw for clamping the articles between the two jaws. The 
operation consists finally in constructing the standard and bed- 
plate with a recess for the introduction of large articles, with- 
out having the drill-stock, or the table or bed-plate, set out at a 
great distance from the face of the standard. 

Drilling Holes in Glass, &c. — A practised man « 
gives it as his experience that a splinter of a diamond (A 
is the best article with which to drill holes in glass. 
The splinters are mounted as in the diagram. A, brass 
wire, is made to fit drill-stock, sawn down a little way 
with a notched knife to allow the splinter to fit tight ; 
B, the splinter of stone cemented by heat with a little 
shellac or sealing-wax. The drill is to be used quite | 
dry and with care. 

Rock-Drilling Machinery. — An improved drill has been in- 
vented by Mr Christian Jurgens, of Weber Creek, California, 
which consists of three angular cutting bits, having an obtuse 
point, thus giving it three regular inclined faces and three 
corners. When the drill has become worn and dull from use, 
the inventor uses a die, by means of which the smith may 
more readily and perfectly restore the drill to its original shape. 
In forming the original drill, the inventor uses a swage block, 
into which the bar of metal, after being heated, is placed hori- 
zontally, where it is hammered and turned until properly shaped 
to receive its cutting faces and points. This swage may be 
also advantageously used in repairing drills, and in keeping 
the drill in proper shape as it is gradually worn up by use and 
the requirements of new cutting edges. By the use of these 



28 MISCELLANEOUS TOOLS, 

shaping tools a drill may be more perfectly and readily shaped 
and sharpened than in the ordinary manner of hammering on 
an anvil. 

Alley's Drilling-Macliine. — This instrument was introduced 




by Messrs Neilson Brothers of Glasgow, and was designed by 
Mr S. Alley of that firm. Its chief peculiarity is that nearly 




all the gearing is enclosed within the hollow pillar and radial 
arm, thus protecting it from the dust and from contact with 



INSTRUMENTS, AND PROCESSES. 



29 





surrounding objects, whilst the tool as a whole is rendered very- 
compact. The pillar, which is of the telescope form, is raised 
and lowered by- 
hand in the smaller 
machines, but for 
larger sizes an ar- 
rangement repre- 
sented in the sec- 
tional view is adopt- 
ed. The wheel and 
screw on the top of 
the vertical pillar on 
the left - hand side 
of the main pillar is 
employed for rais- 
ing a coupling on 
the driving shaft, 
by which means the 

hfting screw is coupled to it. The drill-spindle is provided 
with a self-feeding motion, which can be engaged and dis- 
engaged at plea- 
sure by means of 
a friction - clutch. 
The other parts of 
the machine are 
so clearly shown 
in the woodcut 
that a further de- 
scription is not re- 
quired. 

Boring-Machine, 

— The following 
boring-machine is 
to be used where 
great power is ne- 
cessary : A is 
a stand which 

supports the flywheel B. A cogwheel C revolves on the 
same axle as this flywheel, and turns another cogwheel D, 
which revolves on a pivot, to which is attached the auger E. 




30 



MISCELLANEOUS TOOLS, 



The flywheel is turned by the treadle and crank H. This 
would give sufficient power to the auger to bore through the 
thickest planking. 

Pillar Drilling-MacMiie. — This compact and useful in- 




strument occupies a space of less than 2 ft. square, the height 
being only 5 ft. 3 in. It can be worked as advantageously by 



INSTRUMENTS, AND PROCESSES. 



31 



steam as by manual labour. When worked by the latter, the 
pressure on the drill is produced by the feet, leaving both 
hands at liberty to hold the work and turn the machine. On 
removing the foot the drill is instantaneously lifted out of its 
work ; the pillar being accurately turned, the table is easily 
adjusted to any depth, so as to take in articles not exceeding 
2 ft. 3 in. in height. This pillar drilling-machine requires only 
one person to work it. The drill makes two revolutions to one 
of the hand-wheel, consequently, for holes up to \ in. diameter, 
it will drill two to one of any other machine, and when worked 
by steam power, it retains this advantage up to |-in. holes. 

Boring-Tools. — There are several boring-tools for wheels, 
&c., to follow up drills, or to finish holes left in the castings. 
The rose-bit is of very general use in boring out brasses 
for bearings. It 
is made of steel 
turned, filed into 
teeth, and harden- 
ed. Fig. I repre- 
sents two forms. 
Fig. 2 is the regu- 
lar boring-bit of 
engineers ; it is a semicircular bit of hard steel shown more 
plainly at B ; the other end is drilled to receive the point of 
the back centre 
of lathe, which 
keeps it up to its 
cut. Let the wheel 
to be bored be 
chucked, and after 
being drilled (if 
required) turn out 
a recess the exact 
diameter of the 
tool, thus : ab is the recess ; de^ top of rest ; tr, spanner of 
back centre. Then lay the tool in the recess, flat side up, 
place a spanner on the shank, which is squared, and let span- 
ner lie on the rest so as to prevent the tool from turning, 
screw up back centre, and work away. Holtzapffel keeps 
the standard tools required. 





32 



MISCELLANEOUS TOOLS, 



Sprinkling Book Edges.— Procure for;i-ed edges a penny- 
worth of Spanish brown, and for brown edges a pennyworth of 
burnt umber, and take sufficient paste to mix a quantity of 
either colour on a stone slab, adding, when well mixed, a few 
drops of sweet oil ; then put the mixture into an earthenware 
jar, and add some water to it. Before using it stir it well with 
an iron-bound brush, then twirl the brush well round in the jar, 
and strike it against a wooden rod, held in the left hand, till it 
throws fine spots on a piece of paper ; then proceed in the 
same way to sprinkle the book edges, taking care to wipe the 
wooden rod occasionally. 

Home-made Drill. — A simple drill for small objects can be 

made, as shown below, for about six- 
pence. In fig. I, AC is a shaft of 
common deal, thick where the fly- 
wheel is placed and tapering towards 
each end ; HE is the flywheel, also 
made of deal and weighted with lead ; 
KL is the wood ; and HF, HE, two 
rings of lead : instead of rings a piece 
of pipe flattened might be nailed on 
the circumference. Fig. 2, HZ, ZF, 
shows the breadth of the rings of 
lead ; S is the hole where the shaft 
is fixed. Figs, i and 3, NO is a 
cross-bar working on the shaft ; S' 
is the hole where the shaft passes — 
this must be loose ; N and O, where 
the twine is fixed ; PC is a wire 
wrapping to hold the bit (a small 



;:r>.5 




F1&3. 



cross-bar to Y. Pressure 
and relaxed to the bar. 



bradawl) firmly. 
The working is 
very simple. The 
twine NX, XO, 
must be fixed at 
X, and wound 
round the shaft a 
few times, which 
raises the arm or 
must then be alternately applied 



INSTRUMENTS, AND PROCESSES, 



33 



Grinding and Polishing Pebbles. — Pebbles are ground 
with a lead wheel and emery, the emery to be mixed with 
water to a paste and applied with a small brush ; after they 
are sufficiently ground, the next process is smoothing. Work 
the emery on the wheel, it will soon smooth ; if the wheel 
should get dry or blue, take a little more emery and another 
stone, and smooth it on the wheel and then finish off scratches. 
Now iox polishing. Be sure and wash all the emery off before 
commencing this step. Polishing is done on a block-tin wheel 
with rotten-stone. All the wheels run horizontal, and are 
cast about 8 in. in diameter 
and turned true. 

To Cut Brooch Stones, — If 
the pebbles are round they 
must be slit. This is done 
with diamond-dust, applied 
to the edge of a tin wheel 
with the finger, and then oil 
is kept on with a feather as 
long as you cut ; after that, 
the stones are blocked to 
shape with a pair of soft iron 



nippers 6 in. in size, and 



then stuck on a stick and cut 
into shape and finished. 

Vertical Drilling - Ma- 
chine. — This small machine 
can be fixed upon the bed of 
a lathe, and worked by a 
small pulley on the flywheel 
shaft. A, the bed ; CC, a 
wrought - iron pillar support- 
ing the brackets BB ; EEE, 
screws for holding the brackets ; 
D, hand wheel for raising and 
lowering the drill ; F, bolt to 
the end of the pillar C for holding it down to the bed of a 
lath e. ^^^:^m w^0^ 

Another design is shown in annexed diagram. 

C 




3\ 



MISCELLANEOUS TOOLS, 




work ; L, blocks to keep pulley in position. 



A is a stand of 
hardwood with up- 
right and cross piece 
at top firmly fixed ; 
B, nuts to screw the 
whole to bench ; C, 
flywheel ; D, crank 
for treadle, or may 
be shifted towards 
the outside of fly- 
wheel, and act as a 
handle; E, pulleys ; 
F, lead weights mov- 
ing nearer centre if 
required ; G, pivot 
upon which extra 
weights may be 
placed ; H, pulley; 
I, piece screwed on 
to work in slot in 
pulley ; K, dovetail, 
which may be re- 
moved and plate M 
substitutedjin which 
the squares move 
towards the centre, 
and thus clamp the 




INSTRUMENTS, AND PROCESSES, 



35 



Another simple machine is made as in above engraving, 
can be made of any size to fix on the table conveniently. 
Drilling-machines for stoves, &c., can be made thus : — • 

Fig. 2. .: Fig. I. 



It 




Fig. I shows the tool applied to a work-bench ; fig. 2 as applied 
to a wall. 

Centre Bit for Cutting Leather Washers. — A is a piece 
of iron 3| in. long by \ in. square, tapered at the end to fit into 
a common joiner brace. The bit Ci is to be filed out with a 
small round file for the catch in the brace to fit it. AA is a 
piece of iron i in. thick, i in. broad, i in. long, with a slot 



36 



MISCELLANEOUS TOOLS, 



f in. square through it. B is the slot, D is the centre, the 
same as that of a lathe. CC is the slide, f in. square, to fit in 

the slot. HH is a 




square piece of iron 
I in. lonor 1 in. 



broad. 



thick. 



with 



, I in. 

a slot 4- in. 
square through it. 
FF is the cutter that 
fastens in the head 
HH. G is a thumb- 
screw that fastens 
the cutter in the 
head. HH, the 
cutter, must be the 
same shape as a 
spear-point penknife-blade. The bit Ci in the cutter must 
be filed out so that the thumbscrew can fit in to keep the 
cutter fast. E is for a thumbscrew to hold slide from moving 
when used. 

Water- Wheel. — The leverage in all the weight of water in 
the buckets from D to E is the same as the pressure of a col- 
umn of water of cor- 
responding dimen- 
sions suspended from 
D to F. The shorter 
column CE would be 
also equal to CF ; 
but experience proves 
it to be advisable to 
throw all the force 
into a column of 
water, as above, with 
full buckets, rather 
than to expend velocity at a lower range, the intermediate 
buckets from C to E being only partially filled. This reason- 
ing can apply only to a properly-made breast-wheel. 

Cotton Waste may be thoroughly cleansed from oil and 
grease in the following way : It is put into an iron furnace 
(heated with steam from a pipe led into it), together with a 




INSTRUMENTS, AND PROCESSES. 



37 



little black-soap and soda. The action given to the water by 
the rushing in of the steam keeps the waste continually moving, 
thus freeing it of its impurities. After boiling for about two 
hours, it is taken out and laid on a boiler or warm place till dry. 

To Make the Ram of a Hydraulic Press Water-tight. — 

The ram A is surrounded by a collar of leather D ; the leather 
is formed as shown in fig. 3, being turned up to form a double 
cup, so that it resembles the cuff of a coat-sleeve. When in 
its place, it is kept distended by the copper ring E entering 
the circular channel or fold of the leather. This ring has a 
lodgment in a recess formed within the cylinder B. The 
leather is kept down by a brass or bell-metal ring C, which 
is received into a recess formed round within the cylinder B, 
as shown in fig. i. The interior aperture of this ring is 
adapted to receive the ram A, and thus the leather becomes 
with the edge of the interior fold applied 



confined in a cell, 
to the ram A, whilst 
the edge of the 
outer fold is in con- 
tact with the inte- 
rior surface of the 
cylinder B. In this 
situation the pres- 
sure of the water 
acting between the 
folds of the leather, 
forces its edges into 
close contact with 
both, and makes a 
tight fitting round 
the cylinder and 

ram ; and as the pressure of the water is increased, the leather 
is applied more closely, so as to prevent leakage under any 
circumstances. The metal ring C is truly turned in the lathe, 
I s well as the cavity or cell formed for its reception \ then to 
get it into its place, it is divided by a saw into five segments, 
as shown in fig. 2. Three of the lines by which it is divided 
point to the centre, but the other two are parallel to each other, 
and the ring is put into its place (after the leather and copper 
rings are introduced) by putting in the four segments sepa- 




38 



MISCELLANEOUS TOOLS, 



rately, and the one with parallel sides is put in last. The ram A 
is then put down in its place, and ready for action. The upper 
part of the cylinder above the ring C is filled with tow or other 
soft packing impregnated with sweet oil, which is confined by a 
thin plate or ring. A, piston or ram ; B, cylinder ; C, brass ring; 
Ci, segment with parallel sides ; D, leather collar ; E, copper 
ring ; F, oiled tow. The same letters refer to all the figures. 

Air-Engine. — The principle on which this engine works is 
as follows : — 

The air at the bot- 
tom of A is heated, 
and thus expands 
past the ■ piston B, 
which is made to 
clear ^ of an inch, 
reaches the top, where 
the brickdust cools 
it, thus causing a 
vacuum under piston 
in D, which draws it 
down. 

A, main cylinder 

Dimen- 

dia- 




mam 
regenerator. 



sions 



m. 



meter, 5| in. long. 



Ai, top or 
end of ditto. 



cold 



A2, hot end of 
ditto. 

B, hollow piston working in A, i^ in. diameter, 2>\ ii^. long. 

C, air-tube, connecting A with D. 

D, working cyhnder, i in. diameter, 19-16 in. long. 

E, spirit-lamp or gas-jet. 

F, casing round top of A, 
down heat. 

A, length of stroke = 1 1 in. 
D, length of stroke = 1 1 in. 

Syphon, the Principle of.— Let a bent tube ABC have its 
shorter leg AB immersed in any liquid — say water — having 
been previously filled with the same liquid. The water 



containing brickdust to keep 



INSTRUMENTS, AND PROCESSES, 



39 



will be maintained up to the level D by the force of the 
water in the vessel, and may therefore be left out of con- 
sideration. 

The forces tending to 
move the water in the 
direction DBEC will be 
the pressure of the atmos- 
phere transmitted through 
the water in the vessel, 
and the weight of water 
in the portion BC. The 
forces tending to move 
the water in the opposite 
direction will be the pres- 
sure of the atmosphere 
acting at the orifice C, and 
weight of water in the 
portion BD. 

The pressures of the 
atmosphere being equal will neutralise each other, and there 
will be a tendency of the water to move towards C, in pro- 
portion to the excess of BC over BD. 

A syphon will conduct water from a high to a lower level. 
It is a fundamental law in hydrostatics, that the pressure of 
a liquid upon any point is in direct proportion to the depth of 
that point below the surface. 




Air- Pumps. — i. The following is a suggested air-pump. 
It has not, so far as we are aware, been tried. To work 
it, press the india- 
rubber dome, and 
let it return until 
the air is exhausted. 

A, mahogany 
stand covered with 
a brass plate ; B, re- 
ceiver; C, india-rub- 
ber dome to act as 
pump ; D, wooden 
pad to protect dome from the spring ; E, steel spring to keep 
dome stretched out ; F, brass cyhnder on which dome is 




40 



MISCELLANEOUS TOOLS, 



fastened ; G, valve to prevent return of air into receiver ; H, 
outlet valve, protected by brass cage ; I, screw to let air into 
dome ; J, outlet air passage ; K, exhaust passage. 

2. The following plan will, it is asserted, answer well for 
small experiments : — 

If applied to exhaust the air from a large receiver it should 
be applied only as a finishing pump, as the action is slow 
compared with many double-actioned air-pumps. 



FICI, 



AA, cylinder of brass ; B, piston, which should 
have a thread all the way down ; CCCC, plates 
of brass, with DDD layers of vulcanised india- 
rubber (i inch in the whole) between, which 
are kept firmly in place by means of the screws 
EE. F shows the situation of the tap, the work- 
ing of which is shown in fig. 2. The tap, as 
there represented, should work right into the 
cylinder, but not to interfere with the action" of 
the piston. G is a brass plate, and should be 
ground down so as to fit perfectly air-tight 
to the end of the cylinder and piston ; H is a 
brass cap for the purpose of holding on the 
brass plate G during the first move of the 
piston. 

The pump should be worked in the following 
manner : — 

Screw down firmly, by means of the nuts 
EE, the brass plates and layers of vulcanised 
india-rubber marked C and D in the diagram, 
to the bottom of the piston ; then, having forced 
down the piston to the bottom of the cylinder, 
which is made to fit level to the end of the 
cyhnder, put the brass plate G, with a little 
grease rubbed on the inside face of it, against it — 
this will be kept in its place by the cap H ; then 
the tap being turned so as to open a communica- 
tion with the receiA er, draw up the piston the 
full length of the ( ylinder — this will remove a 
cylinderful of air fi om the receiver ; then eject 
this quantity of air by cutting off the communication with the 
receiver and pushing down the piston. Repeat this process 
till a perfect vacuum is formed. [The above is interesting 



\ 



FIG S 




INSTRUMENTS, AND PROCESSES, 



41 



as a suggestion, 
tested.] 



We believe it has never been practically 




All the pump-plungers are 



Capstan Pumps for Hydraulic Presses. — The arrange- 
ment of pumps for 
working hydraulic 
presses shown by 
our engravings has 
been invented and 
patented by Messrs 
Peel of Manchester. 
The pumps are 
placed in a hori- 
zontal position, with 
their axes radial to 
the circle formed by 
the lid of the cylin- 
drical water-cistern, 
to which all the pumps are fixed, 
connected to an ec- 
centric disc, keyed 
on to the vertical 
capstan shaft, which 
in this manner forms 
the crank for all of 
them, since at every 
revolution of the ec- 
centric each pump 
completes a full 
double stroke. The 
pumps enter the 
corresponding 
phases of their 
movements in rota- 
tion, and divide the 
power very regu- 
larly all over the 
circle. The power is applied direct to the levers of the capstan, 
the form of which, as shown in the drawing, is intended 
for being worked by men. An arrangement is provided 
for throwing the greater number of pumps out of action 




42 MISCELLANEOUS TOOLS, 

when the pressure increases beyond a certain point, so 
that the ultimate compression given to the bale can be increased 
by these means. 




Cork Springs. — In a report upon new mechanical appli- 
cations the secretary of the Franklin Institute called attention 
to the use of cork in place of india-rubber as a support for 
freight cars and like heavy vehicles. One would not be led by 
any means to predict the efficiency of cork in this connection 
from ordinary impressions of its properties. The cork used for 
these springs is of the commonest description, harsh, hard, and 
full of fissures. It is cut into discs of about 8 inches 
diameter, each pierced with a central hole. Previous, how- 
ever, to cutting it, it is soaked in a mixture of molasses and 
water, which gives it some softness and renders it permanently 
moist. A number of these cork discs are placed in a cylin- 
drical cast-iron box, a flat iron lid or disc is placed over them, 
and by hydraulic pressure is forced down so as to reduce 
the thickness to one-half. A bolt is then run through box, 
corks, and cover at the centre, and a nut being screwed on this, 
holds all in place, when the press is relieved, and the box of 
compressed cork disc or cork spring is ready for use. One 
of these springs, placed in a testing machine under a weight of 



INSTRUMENTS, AND PROCESSES. 



43 



20,000 lb., shows an elasticity suggestive of compressed air in 
a condensing pump. One would expect, from the appearance 
of the material, that under heavy pressure it would be pulverised 
or split into shreds, especially if this pressure was assisted by 
violent shocks ; but, in fact, no such action takes place. A 
pressure which destroys india rubber, causing it to split up and 
lose its elasticity, leaves the cork unimpaired ; and with the 
machinery in use, it has even been impossible, with any 
pressure attainable, to injure the cork, even when areas of but 
I inch was acted upon. In connection with this subject, the 
president, Mr William Sellers, remarked, at the conclusion of 
the secretary's report, that he had for some five years employed 
a forging-machine in which a spring of the form and material 
above described was used, and subjected to continual and 
violent shocks, and that its performance had been most 
thoroughly satisfactory, with no signs of deterioration. 

Camera Obscura for Drawing Objects. — The following 
sketch will be useful to amateurs wishing to construct a camera 
obscura. The best form of lens is a Meniscus (the focus for 
sketch 16 in.) with its 
convex side to the mir- 
ror, the diameter 2\ 
in., the mirror 4 in. by 
3 in. K is a hole to see 
the image. One of the 
sides is made to open, for 
the hand to draw the ob- 
ject. The height of the 
camera is 19 in. ; the 
lens to be 15 in. from 
the bottom ; the mirror 
to be as close to the 
lens as possible, at an 
angle of 45°. The mir- 
ror and lens should be x^ (/ru 
made in a square box to fit in the top, so as to allow the sides 
abc to fall in, and d to form a lid. 




Pump for Deep Wells. — A model pump, made by an 
ordinary tinworker, is thus described : — 



44 



MISCELLANEOUS TOOLS, 




The barrel was about the size of a pint mug, the pipe was 
about 3 ft. long. Filled with water, 
it was found that the water in the 
barrel balanced the water in the pipe, 
and remained there by keeping the 
lower end of the sucking pipe under 
water ; consequently, a pump fixed on 
the short pipe C would work with as 
much ease as though the water rose to 
the top of the well. A is an opening 
to fill it with, and while filling, the 
short pipe C must be stopped when 
full. Secure the opening at A, making 
it air-tight. 

This pump will require a valve to act 
with the bucket. For convenience the 
barrel B may be put above, below, or 
half-way with the surface of the ground. 
The opening at the top A may be 
omitted in a miniature model, as it 
will only be required for convenience 
in a large domestic concern. 



V>^ATER LEVEL 



LOWER VALVE 



Pump for Tube Wells. — During 
the Abyssinian War the Government 
supplied various kinds of pumps, of 
which the following was the best ex- 
ample. The whole apparatus is very 
simple and ingenious, being one of the 
numerous American inventions designed 
for the saving of labour, more especially 
in farming and mining districts. 
A well on this new principle may be sunk in from one to 
three 1 ours. The tube of the well is simply an iron gas or 
steam ] ipe \\ in. in internal diameter. 

The lower end of the tube AB in the accompanying diagram 
is furn shed with a solid steel or case-hardened iron spike B 
of the shape of a four-sided pyramid. The lowest end of the 
pipe itself is pierced by numerous small holes at N. After the 
pipe has been driven into the ground, a small pump is screwed 
into the top ; the water, if present in the place, finds its way 



INSTRUMENTS, AND PROCESSES. 



45 



through the holes at N, and may be pumped up to a height 
not much exceeding 28 ft., which is usually all that is neces- 
sary. 

Not the least ingenious aspect 
of this useful little invention is 
the method of driving the pipe 
into the ground with the smallest 
expenditure of time, labour, and 
materials. 

The movable clamp F is 
tightly screwed to the outside of 
the tube, above the level of the 
ground HK. Near the top of 
the tube, some distance above 
A, a similar clamp is fixed, 
which upper clamp carries two 
pulley-wheels for ropes. The 
same ropes also pass round the 
pulley- wheel DE of the monkey 
C, By means of the ropes a 
couple of men can easily pull the 
monkey C up the pipe, and 
suddenly let it fall upon the 
edges of the clamp F ; and the 
force of each blow of course 
drives the pipe deeper into the 
ground. By successive blows 
the clamp F at last reaches the 
level of the ground HK, when 
it is unscrewed and refixed 
higher up the pipe. The upper 
clamp may be shifted in a 
similar manner, and in this way 
the pipe AB can be driven, if 
necessary, as deeply into the 
ground as a pump can raise 
water. 

The advantages claimed for Norton's Patent American Tube 
Well, as it is called, are — 

I. That it costs only a tithe of a bored or dug well, and 
saves water-rates, because by the 11 and 12 Vict. cap. 63, it 




46 



MISCELLANEOUS TOOLS, 



is enacted that no water-rates can be levied where there are 
pumps giving a proper supply of water. 

2. That the water is purer than usual, because of freedom- 
from the upper surface drainage. 

3. That by this method wells may be easily made in loose 
soil, and the strata below may be pierced should there be no 
water at the bottom of the loose soil aforesaid. 

A plan somewhat similar to this has long been in use to raise 
salt from its subterranean beds. Sir Robert Kane, M.D., in 
his book on ^^ Chemistry," says : " Owing to the admixture of 
earthy matters, the rock-salt, as quarried, is generally brownish 
coloured, and hence requires to be dissolved in water and 
crystalhsed for use. The expense of extracting the salt may 
be in many cases lessened by simply boring down to the bed 
with a pipe a few inches in diameter, and letting thereby 
water run in upon the salt ; a strong solution of salt is thus 
produced, which is pumped up and evaporated. The expense 
of sinking a shaft and quarrying out the solid salt is thus 
avoided." 



Sack-Holder. — The diagrams below illustrate a simple and 

FICI J FIG a 




useful invention for sack-holding, inasmuch as it is the saving 
of a vast amount of labour and material. It possesses several 



INSTRUMENTS, AND PROCESSES, 



47 



FlC 3 



decided advantages, combining strength with simple construc- 
tion and direct action. The height can 
be regulated as required by opening or 
closing the legs ee^ being kept in the 
required position by the perforated plate d, 
which is fastened at /, passed through an 
opening in/, and is held by the iron pin g. 

After adjusting the holder to the proper 
height, fold the back part of the mouth 
of the sack outwards, place it over the 
clamping-bar ^, draw the spring arms cc 
forward, and place the hooks over ee ; the 
sack will then be firmly held between the 
bars ab (fig. 2). In this position it 
can be conveniently 





5 



filled by one man, 
thus saving the labour 
of a second to hold 
the sack. When the 
sack is filled it is set 
free instantly by un- 
fastening the springs. 
By a simple modi- 
fication of the above 
the "holder " may be 
adjusted on wheels, 
thus combining with 
it sack-cart (fig. 3). 
It can also be fixed on beams or walls (figs. 4 and 5). 

Diamonds, to Polish. — The plan in use at all the large dia- 
mond-cutters' is simply a circular cast-iron disc of good metal, 
with a vertical spindle running through its centre, balanced and 
turned and faced true in a lathe. The disc revolves at about 
1000 revolutions per minute. With a little diamond-dust and 
oil the stone is set in a small brass cup filled with common soft 
solder ; it is then screwed up in the clamps, and applied to the 
skive till the facet is formed. 

To Fasten Driving Straps. — Two thin metal plates, their 
inner faces roughened like those of a vice, and held together 
by screws, form a cheap, strong, and convenient fastening for 



48 



MISCELLANEOUS TOOLS, 



driving straps. If the strap stretch, the screws (which pass 
between the ends of and not through the strap) have only to 
be loosened, the ends of the leather cut shorter and clammed 
anew. 



To Draw Radii to Inaccessible Centres. — The following 

instrument will be of use: 

A is the blade with a slot 
in one end for set screw 
C to work in. 

BB are the legs to run 
against cylinder, &c. 

DD are radius bars to 
keep the blade central. 

Bookbinding — Mar- 
bling. — Use the follow- 
ing colours : Scarlet drop 
lake, Chinese blue, indigo 
blue, ultramarine, orange 
lead, Dutch pink. Chinese 
blue can only be used by 
grinding with a small 
piece of pipeclay, and 
when properly ground, 
add a little gum arable 
dissolved in water. Ul- 
) tramarine blue, with a 
small portion of indigo, 
makes a good colour, and 
is less troublesome to 
manage, but does not 
stand so well. Green, 
indigo and Dutch pink, mixed to the shade required. Red, 
use scarlet drop lake. All the above colours must be ground 
in neat gin, no water to be used either in grinding or after- 
wards. A few drops of ox gall must be put in each colour to 
make it spread on the size. Use the colours about the thick- 
ness of treacle. 

Size. — This is the principal ingredient in marbling, and 
therefore requires much attention. Use the best gum drachan, 




INSTRUMENTS, AND PROCESSES, 



49 



which should be white and clean ; soak a handful in soft 
water for twenty-four hours, beat well up with a roller, then add 
water until about the thickness of cream ; pour through a sieve 
into your trough, let it 
stand to clear, add a 
little salt, and it is 
ready for use. For non- 
pareil marble use the 
same size, but thinner ; 
and in grinding the 
colours, add a little 
bees-v/ax dissolved in 
turps. 

Gas - Generator. — 

Procure a half-gallon 
jar capable of standing 
a good pressure, then 
turn a cap to fit the 
neck with a screw in- 
side, as N ; then the 
headpiece P, with a 
screw at S to fit into N, 
the head to contain a 
tap moved by a handle 
H, when the water will 
be . forced through the 
glass tube A, which 
must be connected with 
the opening O, and reach 
to within ^ in. of the 
bottom of thejar. To 




work it, fill it three parts full of water, then add |^ oz. each 
of carbonate of soda and citric acid, or a sufficient quantity 
to generate gas enough to force the water up through the 
tube. 



Papier Mache. — The substance known as papier mach^ is 
extensively employed in the construction of tea-trays, picture- 
frames, &c., and even railway carriages. There are two kinds — 
the pasted sheets and the macerated. The latter, which is the 

D 



50 



MISCELLANEOUS TOOLS, 



more common, is made of paper cuttings boiled in water, and 
beaten in a mortar till they are reduced into a kind of paste, 
and then boiled with a solution of gum or size, to give tenacity 
to the paste, which is afterwards formed into different articles 
by pressing into oiled moulds ; when dry it is varnished and 
poHshed. The black varnish for papier mach^ toys is 
thus prepared : Some colophony, or turpentine boiled down 
till it becomes black and friable, is melted into a glazed 
earthen vessel, and thrice as much amber in fine powder 
sprinkled in by degrees, with the addition of a little spirit or 
oil of turpentine now and then ; when the amber is melted, 
sprinkle in the same quantity of sarcocolla, continue from time 
to time to stir them and to add more spirit of turpentine till the 
whole becomes fluid, then strain out the clear through a coarse 
hair bag, pressing it gently between hot brands. This varnish 
mixed with ivory-black, in fine powder, is applied in a hot room 
on the dried paper paste, which is then set in a gently-heated 
oven, next day in a hotter oven, and the third day in a very 
hot one, and let stand each time till the oven grows cold. 
The paste then varnished is hard, durable, glossy, and bears 
liquors hot or cold. 



Wheeled Skates. 




The following sketch is sufficient to 
allow any clever mechanic to 
make a pair of wheeled skates 
that can be used both in and 
out of doors, on any level 
ground. They are fastened 
on the feet with a strap from 
heel to instep, and a couple 
of straps across the toes. A 
screw passes into the heel, at 
the back instead of the bottom, 
as in the ordinary skate. The 
skate itself is formed of iron, 
slightly curved to fit the foot, 
and rolls upon four little 



wooden wheels, with indiarubber tires. 



Omnibus Register. — Various plans have been from time to 
time suggested for registering the number of passengers carried 



INSTRUMENTS, AND PROCESSES. 



51 



in and upon an omnibus during the day. The present plan 
of expecting the conductors to mark down each " fare " upon 
a card is confessedly incomplete, and the more simple one of 




M 



UmniOus jfassenger Registering Machine. 

giving each passenger a ticket from a numbered book does not 
seem to have suggested itself to the omnibus proprietors. 
The following apparatus for registering the number of passen- 



52 



MISCELLANEOUS TOOLS, 



gers conveyed and the amount of money taken has been in- 
vented by Mr R. H. Thomas of Kidsgrove, near Birmingham. 
Fig. I of the diagrams is a ;|-size plan of the machine closed 
ready for use, to be suspended under the left arm by the two 
rings 00 to a shoulder strap, the hollow side next the body, 
and the cover C towards the right hand. 

Fig. 2 is an elevation with the front plate L and the bearing 
bar M removed to show the movement. 

A is a thumbstand on a sliding rod jointed at the bottom 
end to a ratchet hook B and a spring S ; C is a cover for 
protecting the stud A when not in use, but is turned up to the 
dotted lines when it is required ; D is a detent click and 
hammer ; E is a spring to force it down in the ratchet teeth, 
and at the same time to strike the bell R ; F is a plate ratchet 
wheel numbered for pence, from i to 12 and from i to 12, 
with a pinion on its arbour, which drives the shilling plate wheel 
G, with another pinion to drive the pounds wheel H ; I I I are 
_ three indicators point- 

ing to the numbers 
on the wheels F, G, 
and H ; R is a bell 
on the arbour of the 
wheel H. 



Eatchet-Wheels. 
• — RW,ratchetonend 
of wheel nave, both 
cast together ; CC, 
a collar on the shaft 
end which works in- 
side of nave ; C, a 
movable catch kept 
in its place by the 
small spring S. The 
collar answers for 




two purposes — viz., 
to keep the wheel on and to work it round. D is a set screw to 
fasten a tin cap on end of nave or boss of the wheel ; SC is a 
set screw to fasten the collar on the shaft ; WBC, the wheel 
boss and cap fitted on over the ratchet. The ratchet is a rim 
by itself, and may be cast at rights and lefts. 



INSTRUMENTS, AND PROCESSES, 



53 



Cutting out Bowls. — An inspection of fig. i will show 
that after the first groove 



F I C .1. 




ri c . 2, 



is cut, a very long 
straight hook can be 
placed beside the centre 
block, but it would be 
impossible to place it for 
the edge to cut. But in 
fig. 2, a small tool, 
figure I, is shown in 
position, and it can be 
brought to touch, cut 
the block, and when 
gradually advanced till 
the shank of the tool 
touches the block, will 
be undercut to the 
dotted line. Then you 
can place 2 so as to 
begin to cut, it is so 
placed to commence 
where the other left 
off; by the time this 
has been advanced the 
block will be undercut 
to the second dotted 
line. Insert a longer 
one in the same way 
till the block falls out. 
With curved hook tools 
wooden bowls are thus 
cut out one from inside 
another, so as to have no waste 



Ivory Bleaching. — Should antique works in ivory become 
discoloured, their original whiteness may be recovered by 
exposing them under a glass shade to the action of the sun's 
rays. If a piece of sculpture is disfigured with cracks, although 
these defects cannot be removed, they may be rendered much 
less apparent by brushing them over with soap-and-water. The 
process of bleaching will be much accelerated if before exposing 




54 MISCELLANEOUS TOOLS, 

to the sun, the articles are brushed over with calcined diluted 
pumice-stone. 

Ivory Cleaning. — Rub it with finely-powdered pumice- 
stone and water, expose to the sun whilst moist under a glass 
shade, and repeat until the whiteness is restored ; or immerse 
for a short time in water slightly mixed with sulphuric acid, 
chloride of lime, or chlorine, or it may be exposed in the moist 
state to the fumes of burning sulphur, largely diluted with air. 
Ink-stains may be removed by repeatedly using a solution of 
quadrozalate of potassa in water. 

Ivory, to Soften. — Dr Lankester recommends phosphoric 
acid, of the usual specific gravity, which renders ivory soft and 
nearly plastic. When washed, with water, pressed, and dried, 
the ivory regains its former consistency, and even its micro- 
scopic structure is not affected by the process. 

Dyes for Ivory. — Billiard-balls and other articles in ivory 
are often dyed. A good red dye may be given by first imbuing 
the ivory in a solution of nitro- muriate of tin, and then plung- 
ing it in a bath of Brazil wood and cochineal. Lac dye may be 
used with still more advantage to produce a scarlet tint. If 
the scarlet ivory be plunged for a short time in a solution of 
potash, it will become cherry red. To dye a purple the ivory 
must first be mordanted for a short time in the above solution 
of tin, and then immersed in a logwood bath. This gives a 
violet colour. When the bath becomes exhausted it imparts 
a lilac tint. Violet ivory is changed to purple by steeping it 
a little while in water containing a few drops of nitro-muriatic 
acid. The aniline dyes can only be used for mauve and 
magenta, but unfortunately they soon fade. To dye ivory green 
it must first be dyed blue by immersing it for a longer or shorter 
time, according to the depth of colour required in a dilute solu- 
tion of sulphate of indigo, partly saturated with potash. After- 
wards dipping the blued ivory in the solution of nitro-muriate 
of tin, and then in a hot decoction of fustic. By omitting the 
indigo bath the ivory will be dyed a fine yellow. Ivory takes 
the dyes much better previous to polishing. Should any dark 
spots appear, they may be cleared up by rubbing them with 
chalk ; after which the ivory should be dyed once more to 
produce perfect uniformity of shade. On taking it out of the 



INSTRUMENTS, AND PROCESSES. 



55 




boiling hot dye bath, it ought to be immediately plunged into cold 
water to avoid the chr.nce of fissures being caused by the heat. 

A simple way of dyeing old billiard-balls is to procure a piece 
of thin, fine-faced r.carlet cloth, wrap it tightly round each ball, 
being very careful to have as few creases in it as possible, and 
boil in water till the colour has reached the required depth. 
Rough-faced cloth will give the balls a mottled appearance. 

Another plan is to take 2 ounces of verdigris and i ounce 
of sal-ammoniac, grind them well together, pour strong white 
wine vinegar upon them, and put your ivory balls in. Let them 
lie covered till the colour has penetrated. 

Saving Life on the Ice. — Below is a diagram of a proposed 
raft to be used in rescuing persons from drowning consequent 
upon the breaking 
up of the ice. It 
is constructed upon 
the well-known plan 
of the toy regiment 
of soldiers. It 

might be made of battens 5 ft. long, 4 in. by 2 in., 
bolted together, having a few friction rollers ; and 
irons turned up at ends similar to skates. By 
means of the two ropes it could be worked from 
the bank, and got into any desired position with 
great facility. Such rafts would be very useful to cover any 
weak place on the ice, and one or two extended would be 
effectual in keeping it clear of skaters. The whole would 
occupy about 5 ft. square, and when extended would form a 
raft 50 ft. long and 4 ft. wide. 

Vellum Cleaning. — Muriate of tin, oxalic acid, binoxalate 
of potash, of each \ ounce ; powdered pumice - stone and 
cream of tartar, 2 ounces of each, and water 2 pints. Put 
all together and allow to remain till the oxalic acid and bin- 
oxalate of potash are dissolved. Shake well up before using, 
and rub well the bindings with it, by means of a sponge or 
piece of flannel, till clean. The bindings should turn out 
nearly white. Ink-stains will mostly be taken out. It will be 
well not to try to do too much at once, as more good may be 
done by applying a second time, in a day or two, after the 
books have got dry. 




56 



MISCELLANEOUS TOOLS, 



Parchment Cleaning. — Strain the parchment tight with the 
finger and thumb over a ruler, and " shave '^ it out (the very- 
same action being used as when shaving the face) with a very- 
thin sharp knife. The two principal difficulties in this are, not 
bringing the pieces clear off, and thereby leaving jagged ends ; 
and bringing them too clear off — i.e. , making holes. When 
he has mastered this the amateur will be able to cut out a line 
or two, if he hkes, and it will be scarcely visible unless held up 
to the light. 

Tortoiseshell, to Polish. — Handles and similar work are 
first sawn into shape, then filed and scraped with a joiner's 
scraper ; afterwards polished on a buff wheel, first with cal- 
cined Trent sand, and finished on another wheel with oil and 
rottenstone. Flat works are treated in a similar way with flat 
pods. Turnery works are smoothed with fine glass or emery- 
paper, and finished with rottenstone and oil. Horn is treated 
in the same way, but the sand need not be calcined. 

Cutting Hinges. — Amateurs will find the following plans 
useful for cutting the concave parts of hinges : The holes aaa^ 
fig. I, are first drilled to admit the steel rod, fig. 2, which has 

one end squared to 
enable it to be turned by 
a hand-vice. On this 
c^ rod fits the cutter, fig. 
3, which is a cylindrical 
piece of hard steel bored 
to fit the rod, and cut 
with teeth on the outer 
cylindrical part and 
on one fiat surface ; a 
pin is inserted through 
both the cutter and bar, 
so that the two may be 
united after they have 
been placed within the 
joint to be worked. A 
recess must first be cut to admit the cutter, and then the hollow 
parts of fig. i are cut throughout their length with the cutter, 
which afterwards serves to flatten the faces of the knuckles in 
exact parallelism throughout and at right angles to the central 




INSTRUMENTS, AND PROCESSES. 



57 



hole. For cutting the knuckles and tenons for the small joints 
of mathematical instruments, &c., such as fig. 4, the work is 
usually supported on a small iron platform, the surface of 
which is horizontal, with 

a notch to receive the ^ .^ ^^^^^^ FIG. 5. 

saw B (worked by the 

lathe) and a cylindrical 

stem C to adapt the 

platform to the bed-piece 

of the common rest. This 

platform is fixed a little 

below the axis, in order 

to place the knuckles 

exactly central to the 

saw, so as to make the 

notches equally deep on 

both sides, and if the 

surface of the platform 

is parallel with the axis "^\a/7^ 

of the spindle, the notch is sure to be square with the side of 

the work. For fig. 4, E, two saws are used upon the same 

spindle to ensure the parallelism of the sides of the middle 

piece or tenon. Fig. 6 will also answer the same purpose 

without a lathe, by passing a pin through the centre hole and 

working it backwards and forwards in the hinge to be finished. 




'y^yW-yyyy7/^'</yyy:'yy, ■y'y'^^>yA^yy>:'y^y'^^: 



Kaleidoscope. — Below is a suggested improvement upon the 
old style of kaleidoscope. It claims to be better inasmuch as 
the body of it does not require turning. The objects change 
by turning the small 
shaft that drives the 
wheels. The large 
one is only a toothed 
rim, into which is fixed 
a tin case with a glass 
at each end, between 
which are fragments 
of coloured glass. The 
whole is fitted in a box with ground glass at one end and a 
convex lens on the other. 

The simplest form of kaleidoscope consists of a cylinder of 




58 MISCELLANEOUS TOOLS, 

tin, in which two plain rectangular mirrors of polished metal, 
or of glass having the back blackened, are fixed at such an 
angle of inclination to each other as may be obtained by divid- 
ing 360° by the numbers 3, 4, 5, 6, 7, 8, &c. The cylinder is 
covered at one end with a circular plate of metal, having a 
small hole in the centre, while a rim of metal is fitted over the 
other end, which is so constructed that two circular pieces of 
glass may be fixed in it at a short distance from each other, 
having some pieces of coloured glass, beads, lace, feathers, &c., 
in the space between them. The piece of glass that is placed 
at the extreme end of the cylinder should be ground glass, so 
that while the light is admitted into the interior of the instru- 
ment, external objects may be prevented from becoming per- 
ceptible to the observer. An angle of 60° is perhaps the best 
angle of inclination for the mirrors, as it may be readily deter- 
mined, and affords a sixfold repetition of the pattern, which 
presents a tolerably uniform appearance of colour in all parts. 
If the angle of inclination be greater than 6q°, the pattern will 
not be multiplied to so great an extent, but if less, although 
the pattern will be repeated a greater number of times, it will 
lose considerably in brilliancy at and towards the parts where 
the reflections of the pattern meet by the frequency of the 

multiplication. In some 

^,^-'''' '"''-y^ kaleidoscopes the mirrors 

,-'' \ / '\, are made trapezoidal in 

/' \ "P / \ form instead of rectan- 

/ \ / \ gular, the broader ends 

/ d ^\ / ^ \ being placed at the lower 

* \ / \ end of the tube. 

i ^_^J&^^^ ^..\ The principle of the 

; y"^ / \ ^\ ; kaleidoscope will be un- 

\ ^ / / \ \ ^ ''' derstood from the accom- 

\ I / \ \ ! panying figure, in which 

\ [ / \ I /' the smaller circle ABC 

^\^ \ / d \ I /' represents a section of the 

'^/ V''' tube of the instrument, 

\^-- --wZ and AB, AC sections of 

""'^ the mirrors, which are 

represented as inclined to each other at an angle of 60°. The 
objects in the space a between the glasses are seen directly by 
the eye, the part of the pattern in the space b is formed by the 



INSTRUMENTS, AND PROCESSES. 



59 



reflection of the objects in the space a^ in the mirror AB ; and 
the part C, by the reflection of the objects in the space a^ in 
the mirror AC. These reflections are again mutually reflected 
by the opposite mirrors, and form the part de of the pattern 
while the images reflected in each mirror (or the third time 
unite in the party", so as to form a correspoi ding appearance 
to the other parts. It is manifest that unless the angle at 
which the mirrors are inclined be accurately determined the 
reflections will not coincide, and the pattern will not be com- 
plete in the part/ 

Kaleidoscopes are made in which the angle of incidence of 
the mirrors may be varied at pleasure, and l:y the aid of a 
lamp and a system of lenses in connection with the instrument, 
the pattern may be projected on a screen in an enlarged form, 
like the image thrown from a slide in a mr gic lantern. A 
pleasing effect of a similar nature, in which tl e images of the 
original object are multiplied and produced in different direc- 
tions, may be produced by fitting the edges of three, four, or six 
trapezoidal mirrors together, so as to form a 1 ollow prism, and 
putting them into a tube similar to that in wh ch the two mir- 
rors of the ordinary kaleidoscope are inserted. Instruments 
of this kind, which 
were invented by 
Dr Roget, are 
called polycentral C 
kaleidoscopes. 

Bevel - Wheels. 

— To strike out a 
pair ofbevel- wheels. 
The following is the 
method of finding 
the taper or bevel 
for any line or 
angle : Let the 
line AB represent 
the shaft coming 
from a wheel, draw 
the line CD to in- 
tersect the line AB in the direction intended for the motion 
to be conveyed, and this line CD will represent the shaft of 




MISCELLANEOUS TOOLS, 



the bevel-wheel which is to receive the motion. Suppose, then, 
the shaft CD to revolve three times whilst the shaft AB 
revolves once, draw the parallel line FE at any moderate dis- 
tance (suppose a foot by scale), then draw the parallel hne 
FG at 3 feet distance, after which draw the dotted line FH 
through the intersection of the shafts AB and CD, and 
likewise through the intersection of the parallel Hne FE and 
FG, to the point H, then FH will be the pitch-line of two bevel- 
wheels. 

Feathering Float. — The following design for a feathering 
float of a paddle-wheel is stated to have the following advan- 
tages : — 

The float keys are in a vertical position during an entire 
revolution of the wheel ahead or astern, thereby making a clean 

feather. The 

paddle - wheel is 
no heavier than 
the oldest style of 
paddle-wheel. It 
has also a jour- 
nal-bearer at the 
extremity of the 
shaft, which is 
a decided im- 
provement on the 
present 
feathering 
wheel. 

Suppose 

to lose her rudder. 

When all other 

means of steering 

lost, the ship 




patent 
- float 

a ship 



are 

can be steered by this wheel by angling the floats by means 
of a handle or wheel conveniently placed on deck, without 
interfering with the speed of the engines. 

Amateur Lens Grinding. — The process of grinding 
lenses for telescopes, cameras, &c., is much more simple than is 
usually supposed. If you wish to grind a lens for a telescope, 
first determine the length of focus and diameter of lens for the 



INSTRUMENTS, AND PROCESSES. 6i 

object glass, and make a drawin gon paper ; you will then find 
by the drawing the thickness of glass required. We will sup- 
pose you commence on a small lens of i^ inches diameter and 
of 15 or 18 inches focus. You must draw two short lines par- 
allel to each other i^ inches apart, next open a pair of compasses 
to 5 inches and draw a portion of that curve between the lines, 
as in fig. I. Next procure apiece of plate glass of the thick- 
ness shown by the drawing, and nibble it round with a pair of 
pliers, using a circular piece of paper as a guide. Smear one 
side of the glass with pitch, and stick it on a cylinder of wood 
of the same diameter and 3 inches high; the crown lens will 
then be ready for grinding. 

The tools for grinding are either of iron or brass, brass 
being best. Take a piece of thin zinc twice the width of the 
lens, and with the compasses at 5 inches describe a portion of 
that curve across the zinc, and separate the zinc at the curve ; 
you will then have a couple of patterns to get the brass tools 
made by. If you do not possess a turning-lathe, go to a wood- 
turner's and get two patterns made to fit the zinc gauges ; the 
patterns must have a stud on each, as in fig. 2, whereby to 
fasten a bit of wood with pitch, to act as a handle. After the 
patterns are cast in brass they ought to be again turned to fit 
the gauges, and finally rubbed together with emery until they 
fit each other. An amateur need not have the tools much 
larger than the lens. 

Next procure from an emery-grinder three kinds of emery, 
\ lb. of the finest washed emery, i lb. fine-grained emery (a little 
coarser than flour of emery), and i lb. coarser still. Begin and 
rub the glass with the coarse emery with water, using the hol- 
low brass tool until the glass is ground of the same curve as 
the tool. At this stage you will not be able to see through it, 
because of the great hollows dug into it by the particles of the 
coarse emery. Therefore wash away all coarse particles and 
rub again with the next degree of emery, which will put a finer 
surface upon it. Wash all this off the glass again, and with 
the finest emery put the last grain on the glass previous to pol- 
ishing, using a strong magnifier to look for scratches ; being 
satisfied the lens has a fine equal grain all over and free from 
scratches, wash all clean and prepare the polisher. Procure 
\ lb. of the finest putty powder, warm the brass tool and smear 
the inside of it with pitch ; lay a piece of fine cloth over the 



62 MISCELLANEOUS TOOLS, 

lens and turn up the tool with the pitch upon it ; the cloth will 
stick to it, and when cold smear the cloth with the putty powder 
and water, rubbing the lens until on looking with the eyeglass 
no trace of the effects of the fine emery is seen. Warm the 
lens before a fire, slide it off the wooden holder, wash the pitch 
from the lens with turpentine, spirits of wine, or other solvent, 
and you will have ground and polished a plane convex lens of 
lo inches focus, it being a rule in optics that a lens ground on 
one side only will have its focus at twice the radius ; but ground 
on both sides, will have its focus at the radial point. You 
must now turn the other side, taking care of the feather edge 
as you approach it, by not going so far with the coarse emery. 
When the second side is finished, you will have a crown lens 
of 5 inches focus. To make the terrestrial telescope an achro- 
matic one, add a concave lens of flint glass to it. 

We will suppose the crown lens is finished ; but as its form 
is thick in the centre and thin at the edge, it will be similar to 
a circular prism, and Avould show all objects with the chromatic 
colours ; another lens must therefore be ground that is thick 
at the edge and thin in the centre, to counteract the dispersive 
power of the convex lens, and as flint glass has in general twice 
the specific gravity of crown, and consequently has twice the 
dispersive power, it will of course do the same amount of 
work Avith one-half the angle of the crown lens, as in fig. 3, 
and so reunite the coloured rays and form again white light. 
Accordingly grind one from the bottom of a flint-glass tumbler. 
Grind it on a flat stone to the proper thickness, and also get it 
to the diameter by taking a strip of sheet iron an inch wide 
and bend it so as to form a collar ; by putting emery and water 
betwixt the collar and the glass, by pinching the collar with 
the fingers while the glass revolves on the nose of a wooden 
chuck, it will be reduced in a few minutes. After it is the pro- 
per diameter and thickness, commence rubbing it on the convex 
tool and finish it in the same manner as before ; you will now 
have a concave side finished which will fit the convex lens ; 
take it off the holder and turn the last side up, and now learn 
that it is a very difficult thing to grind and polish a surface 
truly flat, so that you had better grind the last side concave 
upon a tool of a large radius, say 30 inches. The two glasses 
must then be cleaned and made warm gradually before a fire ; 
a drop or two of Canada balsam being let fall into the concave 



INSTRUMENTS, AND PROCESSES. 



63 



lens, drop the convex one on it, press the air bubbles out, and 
when the balsam sets you will have a small achromatic lens. 
The streaks or striae in the bottoms of tumblers are not of 
so much importance in a terrestrial telescope. Some of the 
best photographic lenses have air bubbles, and some when 
accidentally cracked work quite as well as before. In 
astronomical telescopes the glass must be of the purest 
kind. 

Now take your compound lens and try its focus by the sun, 
and make the tube 3 or 4 inches longer, so as to support the 
magnifying tube called the eye-piece. The object lens will form 
an image of anything within the tube, say the clock-dial of a 
distant church — the tube called the eye-piece merely magnifies 
this image, and a 



n c 




Fl C.3 



> ( > ( 



^ 



variety of eye- 
pieces may be 
used for the same 
object glass, ac- 
cording as a high 
or a low power 
is required ; in 
short, a telescope 
may be compared to a camera obscura, with a microscope 
attached, to enlarge the image formed by the object glass. 

Now then about the eye-piece. The subjoined formula may 
be taken, because the lenses for it are all pianos, so that you 
will only have to grind one side of them, if a piece of plate 
glass be used. Focus of front lens i fths, ditto of second lens 
i|ths, ditto of third lens ifths, ditto of lens next the eye l gth. 
The first and second lenses may be a little under \ inch dia- 
meter ; the third or field lens may be a little more than ^ inch 
diameter ; and the lens next the eye may be about fths dia- 
meter. 

Make two short tubes if inches long (they are called cells), 
and fix your lenses to each end of the two tubes or cells, then 
take a tube called the eye-piece 6| inches long, and slide the 
two cells into each end of this tube ; you will then have an eye- 
piece which must slide into the larger tube to focus on the 
image formed by the object glass. 

In the following machine for grinding and polishing speculum, 
A is the base, / is the worm-shaft which drives the worm-wheel 



64 



MISCELLANEOUS TOOLS, 



b, and this is bolted to a spur-wheel c, both of ninety. They 
turn on a stud g, and are made with a circular flange near their 
periphery, the lower surface of which bears upon a trued part 
A, and the upper gives a firm support to the speculum and its 
cistern (not shown in the engraving). The wheel c drives an- 
other of fifty-two not seen, but attached to the lower surface of 



the cam d ; in the groove of this is engaged a 
lower surface of the cam lever e. 



pm, 



fixed in the 



which is thus made to vibrate 
as the cam revolves. The lever has a series of holes, to any 
of which can be attached one end of a link, whose other end 
is connected with the upper or sliding-plate B, which thus by 
the rotation of the cam is made to vibrate to and fro according 
to any required law, the actual law being that of uniform 
motion. The plate B carries a strong spindle k, on which 

vibrates the arm /. 
This arm can be at 
pleasure either held 
in position by the 
connecting-link k, or 
made to vibrate by 
the revolution of the 
variable crank /, 
which is driven by 
a shaft at the back 
of the slide-plate B. 
The arm carries a 
variable crank m^ 
which can be driven 
either quickly by the 
shaft and pulley «, 
or slowly by the 
worm-wheel o. The 
pin of in drives the 
polisher. If it be re- 
quired to give Lord 
Kosse's action, the crank 7n being fixed, and its pin set central, 
the crank / is set in motion ; this gives the primary stroke, and 
the reciprocation of the slide plate B gives that of the eccentric. 
If the worm-wheel o be made to act, at the same time a light lever 
attached to m will carry round with a slow motion the polisher by 
a stud projecting at its circumference. If it be wished to have 




INSTRUMENTS, AND PROCESSES, 65 

Mr Lassell's motion the crank / is stopped, and it is fix^d in 
such a position that the pin of m shall be at the required dis- 
tance (equal radius of S) from the centre of the speculum, the 
arm i being held firm by the link ; the pin of 7n is next set to 
the distance which equals radius of G, and it is driven by n. 
In this case, however, there is no provision to secure the rota- 
tion of the polisher. The eccentricity can also be given by 
means of B, and as it can be made to vibrate slowly on each 
side of this to any required extent, the effect of Mr LasselFs 
last improvement is given to perfection. Mr Grubb decidedly 
prefers the Rossean action for grinding, but thinks the other 
less likely to fail in the polishing with unpractised hands, and 
uses it himself. He begins with a large eccentricity, and gra- 
dually diminishes it, which can be done without stopping the 
machine. His polisher is made of wood with peculiar care. 
It is formed by six layers of mahogany, each 5-i6ths of an 
inch thick, and not continuous, but built up of pieces 3 in. 
square ; these are only glued where they cross, being, at least 
in the interior, not in close contact at their edges, and the direc- 
tion of their grain is varied as much as possible. The disc, 
when turned true, is plugged at the edges, varnished, and coated 
with tinfoil at the edge and back. It is the same diameter as 
the speculum. He uses pitch alone, rolls it in the same manner 
as Lord Rosse, cuts it into squares of | in., and attaches them 
to the surface, warming it by a spirit lamp. The machine 
measures about 3 ft. every way, and can work a 2 ft. speculum. 

Power of Lenses. — The magnifying power of lenses is deter- 
mined by the focal length and the density of the glass of which 
they are composed. In the case of a telescope, the power may 
be calculated approximately by the following rule : — If the 
focus of the eye-piece be i in., the number of inches in the focal 
length of the object-glass will give the magnifying power ; if 
the eye-piece be J-in. focus, the power will be twice as great as 
with the I -in., and so on in proportion. 

The following is a more full explanation of the mode of as- 
certaining the power of a telescope. First focus it accurately 
upon a distant object. If now you turn the object-glass up to 
the sky, and remove your eye to some distance from the eye 
end, you will perceive a circular spot of light upon the eyeglass. 
This is an image of the object-glass, diminished in the exact 

E 



€6 MISCELLANEOUS TOOLS, 

ratio of the magnifying power of the instrument. If then you 
will measure the precise diameter of this image upon a finely- 
divided scale (assisting your vision, if necessary, by means of a 
magnifying-glass), and will then ascertain the diameter of your 
object-glass by the aid of the same scale ; the division of the 
latter sum by the former will give the magnifying power of the 
instrument. Thus, supposing that the aperture of your object- 
glass is 2 in., and the little circle of light in the eye-piece is 
•08 in. in diameter, the telescope will magnify exactly 25 
times ; or, assuming that you have a i|^-in. object-glass, and 
that the projected image on the eye-piece measures -08 in. in 
diameter, your instrument would then magnify 1875 0^ about 
19 times linear. In obtaining the magnifying power of a single 
lens, we proceed upon the assumption that the distance of 
distinct vision is 10 in. If now we find the focal length of 
the lens, and divide i o in. by it, we shall get the magnifying 
power. For example, a lens of i-in. focus magnifies 10 times, 
one of l^-in. focus 20 times, one of ^-in 40 times, and so 
on. The focal length of a lens (when not very short) may 
be obtained with considerable accuracy by projecting an 
image of the sun upon a card, by means of the lens whose focal 
length is to be measured, and when such image is accurately 
defined, measuring the distance between the lens and the card. 
This may be conveniently accomplished by mounting the card 
at the end of, and at right angles to the length of, a graduated 
scale, and sliding the lens along the scale with its diameter 
parallel to that of the card. In the case, however, of a lens of 
very short focus, this method becomes impracticable ; and we 
may then have recourse to the admirable mode invented by 
that excellent astronomer, the Rev. T. W. Webb, which we 
cannot do better than describe in his words. ^^ Three pieces 
of cork are perforated by a knitting-needle, so as to slide along 
it. To the centre one is attached, in a vertical position, and 
with its axis parallel to the knitting-needle, the lens to be 
measured ; in each of the others is inserted a piece of a sew- 
ing-needle with the point uppermost, and having its length so 
regulated that a line joining these points would pass, as nearly 
as may be, through the centre of the lens. The cork discs 
carrying these needles are then moved backwards and forwards, 
till the inverted image of the one needle's point, formed by rays 
passing through the lens, is seen coincident and equally dis- 



INSTRUMENTS, AND PROCESSES, 



67 



tinct with the other needle's point, when both are viewed at 
once, through a tolerably strong magnifier applied to the eye, 
and directed towards the lens. Then if the needle-points are 
sensibly equidistant on each side of the lens, a condition which 
can be quite sufficiently attained in the course of a few trials, 
it is evident that they occupy the conjugate foci, and the 
distance between them being carefully measured with com- 
passes will be, as a very simple proposition in optics will show, 
four times the amount of the focal length of the lens for 
parallel raysT' 



Screw-Propeller. — The primary consideration of the appli- 
cability of a screw-propeller to the work it has to do is its 
'* pitch,'' that is, the length in which the screw-whirl makes a 
complete turn round its central axis, and this ^^ pitch " is either 
" finer " or " coarser," as the length of the axis AB is shorter or 
longer ; or in other 
words, as the turns 
of the screw are 
closer together or 
further apart. It is 
evident that if there 
be no '' slip," that 
is, if the screw re- 
tains full hold upon 
the water, as a car- 
penter's screw does 
upon a board — that 
in every revolution 
of the screw-pro- 
peller a distance of 
the length of the 
axis of the full turn 
of the screw will 
have been accom- 
plished by the 
vessel. If thus the 
'' pitch " of the 
screw be 40 ft., 
that is, if from A to B be 40 ft., then every full revolution of the 
screw will, if there be no ^^ slip,'' advance the vessel 40 ft. 




68 



MISCELLANEOUS TOOLS, 



through the water. From repeated experiments it has been 
determined that the best form which can be given to a screw 
is that of two halves of a spiral feather, placed on opposite sides 

of the axle of the 
^ -i^ ^ screw in reverse 

positions ; these, 
^ while they occupy 
only half the space 
in length which they would otherwise require, are found, 
with equal surface, more efficient than the continuous spiral 
formerly in use. The rectilinear edges AB and GH of 
the ordinary screws are highly disadvantageous, on account of 
the shake of the screw caused by the sudden and violent re- 
actions of the disturbed water in that place against the blades 
of the screw as they enter and emerge from thence — since the 
whole of an edge enters and leaves at once the water on each 
side of the aperture ; within which aperture the water is com- 
paratively in a quiescent state; but if the leading edges of a screw 
blade were curved as A/B, G/H, they would slide obliquely and 
continuously through the water. . . . The curved edges have, 

beside, the advantage of throw- 
^ ^ ^ ing off any floating materials 

that may come in contact 
i with them " (Sir Howard 

Douglas on " Naval Warfare 
with Steam "). The pitch of screws vary with the ratio of the 
circle described by the screw to the midships section. 

For 1-bladed screws {MoleswortJis for7nula). 
Ratio of screw's disc to \ 




midships section being 
I to 
Ratio of pitch to the dia- 
meter of screw is i 
to 



6 5 4i 4 3^ 3 2| 2 
•8 1 '02 I'll I -2 I -27 I '3 1 I '4 I '47 



Gyroscope. — To make a gyroscope, get a brassing AAA, 
about 5 • in. in diameter, ^ in. broad, and \ in. thick, 
having a projection B at one part. On the flat surface of 
the ring, near to B, must be a small lump C, also another 
just opposite D. These must be screwed on by two small screws 



INSTRUMENTS, AND PROCESSES. 



69 



each, and are for the purpose of holding the spindle EE, which 
must turn freely on^ F I C . I 

these centres. At' >^ ^ ^ 

the middle of this 
spindle must be 
fixed the disc FF, 
which should be 
about two or three 
times as heavy as 
the ring. A hole 
must be drilled 
through this spindle 
at some convenient 
part for the string. 
The method of us- 
ing is this : — The 
hole in the spindle must be threaded with a piece of string, and 
the disc turn round, 

^ F 




strmg 



1 



El 



u 



n 



winding the 
up the same as is 
done with a hum- 
ming-top. The string 
is then drawn sharp- 
ly out, and the disc 
made to spin rapidly 
round. If the in- 
strument is then sup- 
ported by a loop of 
string, or on a point 
at B,it will (instead of falling to the ground, as might be supposed) 
remain in a horizontal position, moving round B as a centre. 
(See engraving.) The ring AAA should be placed horizontally. 

Another method, identical in principle, but differing slightly 
in detail, is as follows ; — 

The wheel is brass, turned to the shape shown in sketch ; 
the axis of the wheel is steel. The wheel is first bored for the 
reception of spindle ; then the spindle is driven in after being 
cut to its proper length, and drilled with very fine centres ; it is 
then turned on its own centres perfectly true. A lathe with 
two dead centres is the best for turning it. After it is turned, 
the ends of the spindle are properly hardened. A small hole 



70 



MISCELLANEOUS TOOLS, 




is inserted in one end of spindle for reception of twine. The 

way to harden the 
ends of the spindle 
is this : — Get a plate 
of iron about g in. 
thick; bore a hole in 
it just large enough 
to admit the end of 
the spindle, then 
place it on the fire 
(a small slow fire). 
Fill the upper recess 
of wheel with cold 
water, to keep the 
brass cold. 

The ring is made 
of brass, is about \ 
in. thick and \ in. broad, with two bosses in the direction of 
the centre line. These bosses are bored and tapped about 
3-i6ths or \ in. for the reception of steel screws. The ring is 
bored out, and filled up until the ring is equally balanced ; if 
the ring is not balanced, it will not hang horizontally as it 
rotates round the point, but the heavy side will hang down, and 
cause it to "waver." One steel screw is ground to a sharp 
point at both ends, with a square shoulder to screw it in with. 
The point of these screws are hardened, the other screw has a 
square head with a sharp centre drilled in it. A small steel 
bracket is secured by this screw, as shown in sketch. This 
bracket has a sharp centre in it made with a sharp centre 
punch to rest on the point of upright spindle ; this bracket is 
also hardened. The upright spindle is made of steel, screwed 
into a base of lead, as shown in sketch. The spindle is turned 
and ground to a very sharp point, then properly hardened. 
The wheel will not only revolve horizontally round the point, 
but will revolve when placed perpendicular by placing the 
centre in head of screw (as shown) on the point of spindle ; it 
will also spin on the point of the other screw if placed on a 
plate or any smooth surface. After the points of spindle or 
axis of wheel are hardened, the points of screws being soft, the 
wheel is spun round a few times to grind the centres to fit 
each other. After that the points of screws are hardened. 



INSTRUMENTS, AND PROCESSES. 71 

Telescope, to Make. — To make a Galilean telescope the fol- 
lowing articles are required: — A double-convex lens of 5-ft. focus 
and 2-in. diameter ; a double-concave of i-in. focus and about 
i-in. diameter ; a large tube of tin-plate, zinc, or cardboard, 4-ft. 
8 in. long, and 3 in. diameter ; a cylinder of vv^ood, turned to fit 
tightly in one end of the large tube, and having a central hole 
of about I in. diameter bored through it ; and a small tube for 
the eyeglass 6 in. or 8 in. long, and of just sufficient diameter 
to slide into the central hole of the cylinder. The section will 
explain the use of 

these articles. A ' ^ ^ 

is the large tube ; /\ ^ ^ ^, , 



B, the object-glass ; 

C, the wooden ^~' " 
cylinder ; D, the 

eye-tube ; and E, the eyeglass. 

The object-glass and eyeglass must be at a distance from each 
other equal to the difference of their focal lengths, and the 
power will be equal to the number of times the focal length of 
the eyeglass is contained in that of the object-glass. In the 
present case this is 60. 

Tin-plate is the best and cheapest material for the tube, but 
in reality it matters little of what it is made, so that it be 
straight and not too heavy. Its interior should be coated with 
a mixture of lampblack and turpentine. A diameter of three 
inches is best, in order to decrease the liability of flexure which 
very narrow tubes possess, and also to give more facihty in 
mounting the object-glass. 

In purchasing this article, it is much the better plan to buy- 
one from the optician already centred ; but if" such cannot be 
obtained, one should be selected the edges of which possess an 
uniform thickness. In such a one the optic axis will not be 
very far from the actual centre. In mounting it, glue it be- 
tween two circular rings of cardboard, whose outer diameters 
just fit the large tube, and with a central circle cut out of each 
i^ in. in diameter. The lens must be fastened between these, 
so that its centre will coincide as nearly as possible with the 
centres of the cardboard circles. It should be placed an inch 
or two within the tube, as it is then better defended from 
injury than when at the very extremity. 

A ring of iron wire soldered within the tube will do to rest 



MISCELLANEOUS TOOLS, 



the mounted lens upon, and another ring of wire pushed down 
upon it will hold it firmly in its place. These rings are shown 
in the section by the four black dots, two on each side the 
cardboard mounts of the object-glass. The eyeglass may be 
fitted in a similar manner. The length of the wooden cylinder 
should not be less than 2 in. 

In making the Galilean, or any other telescope, the one 
great thing to be attended to is to keep the centres of all the 
lenses coincident with the axis of the tube, and their planes 
at right angles to it. Inattention to this is certain to injure 
the performance of the telescope, however good its glasses may 
be. Most of the failures in amateur-made telescopes that have 
come under my eye have arisen from this cause. It will be 
seen that a first requisite to success on this point is to make 
the tube perfectly straight and rigid, and its section perfectly 
circular. The wooden cylinder should be turned perfectly true, 
the hole drilled through it perfectly central, and not the slightest 
lateral play allowed to the small eye-tube. Though in none 
of these particulars is absolute perfection attainable, yet any 
one making a telescope should never forget that the nearer 
he can approach it, the more satisfactory will his instrument 
be. 

There is one point to which the attention of all beginning to 
handle lenses should be directed, and that is, to avoid wiping 
and rubbing as much as possible. Remove any dirt that may 
fall on the glass by blowing it away, and remember that the 
definition of a telescope is much less injured by a deposit of 
dust on the object-glass than by the numberless small scratches 
which much wiping invariably causes. 

The cost of this telescope is as follows : — Object-glass, 
2s. ; eye-glass, is. ; tube (if home-mad^) of tin-plate, is. 
6d. ; wooden cylinder, lampblack and turpentine, say 6d. 
more ; total, 5s. It will show well Jupiter's moons, and 
more conspicuous belts, Saturn's ring, and one or two of 
his moons on favourable nights, the phases of Venus and 
Mars, the hills and valleys of the lunar surface, and the 
solar spots splendidly, together with many nebulse and 
double stars. 

A stand for our telescope must not be forgotten. A poor 
telescope on a good stand is greatly superior to a good tele- 
scope or a poor stand. 



INSTRUMENTS, AND PROCESSES, 



73 



Telescope Stand. — An excellent stand was made a few 
years ago; on the following model : — 

It is made of deal ; the advantages are steadiness, the work 
being thrown into triangles, the steadying cords and weights 
checking all vibra- 
tion. The spindle 
may be placed and 
adjusted to the 
position of a polar 
axis, and by fix- 
ing pins on per- 
manent blocks in 
the ground, with 
brass sockets on 
the bottom of the 
legs, the stand 
may be always 
placed in the same 
position. There 
may be various 
changes in the 
position of the 
cords and weights. 




The first use made 

of them was to 

steady the end of 

the telescope put 

through a window 

by cords and 

weights in the — 

position figured, where CCC are cords, and T telescope. 

Made in two movable parts, feet of one 
A, of the other BB ; hinged together at 
HH ; E, screw-bolt ; F, cross-piece from 
fore to hind part ; CCC, steadying cords, 
with weights W and W^, the latter running 
on pulley P ; SS, spindle turning in brass 
bearings ; Y, iron supporting the sides of 
telescope on two screw-pins. 

The Y spindlehead suspending the 
sides of the telescope is much steadier than 




a swivel-joint 



74 



MISCELLANEOUS TOOLS, 



under the telescope tube. 
6 ft. 



Height to pivots of telescope about 



A good "Dead-Black" for Telescopes, Cameras, &c., is 

somewhat troublesome to make. Take some ordinary French 
polish, or dissolve some shellac in methylated spirit, and add 
lampblack until the happy medium is attained, that when 
applied to a piece of warm brass, it shall dry a dead-black. If 
it dries with a dead-black surface which rubs off, more polish 
or shellac must be added ; if it dries bright, more lampblack. 

Another plan is to put the brass-work into dilute nitric acid 
to take off any oxide, and put it into a solution of bichloride 
of platinum ; when it has changed colour, brush the work 
sharply up with a brush and dry blacklead, after which 
lacquer it. 

A third method is to take lampblack and mix it with water, 
and just sufficient size to keep it from rubbing off. 

To Cut Microscopic Sections of Wood. — The following 
engraving is half-full size of a machine for cutting thin sections 
of objects for microscopic examination, which has been in use 
for some years, and which is one of the cheapest, simplest, and 

most effectual that could be de- 

» ^ vised. AB represents a piece 

of ^-in. brass tubing, with a 

flange CD, of about 2\ in. in 

diameter, at the end A, and with 

a female screw tapped at the end B 

to receive the capstan-headed screw 

E ; F is a brass plug or piston, 

which is driven up the tube in a 

perfectly obvious way by the screw 

E. This screw has 30 threads to 

the inch. A razor ground flat on 

one side, to slide accurately over 

the upper surface of the flange CD 

(which must itself be quite true^, 

completes the apparatus. 

The mode of using it is simply this : — The wood, or other 

substance of which a section is to be made, is to be driven 

down the tube at A. The screw is then turned until the object 

to be cut projects slightly above the mouth of the tube, and the 



c 



B 



INSTRUMENTS, AND PROCESSES. 



75 



razor is slidden across it, taking off a slice of the material, and 
reducing it to a level with the surface of the flange. By turn- 
ing the screw again to a small extent, and again sliding the 
razor (which should now be wetted) across the flange, it is 
perfectly clear that we may remove a slice of wood of any 
tenuity we please, its thickness being regulated by the extent 
to which the screw is turned. The sections thus made may 
be conveniently washed off into a cup of water, to be taken out 
as required. 

Several more or less elaborate pieces of mechanism may be 
purchased at the optician's, at prices varying from 15s. to ^4 ; 
but none will do their work more effectually than that described, 
which ought not to cost more than six or seven shillings. 

Another Cutting-Machine. — B, a block of wood with a hole, 
into which is fitted C, a brass tube ; D, a brass plug or lift 
accurately fitted, and having two studs S to work in correspond- 
ing slots in C ; E, an iron pin without head fixed with D — pitch 
25 threads ; H, a 
brass nut, the top 
fitted to C, through 
it works E. The 
nut has two collars 
or flanges, M and N, 
and between is O, a 
split collar, which is 
screwed on to the 
box B. This collar 
keeps the nut in 
place, and yet allows 
it to be turned ; XX, two studs to turn the nut H ; Z, a bend- 
ing screw to keep object in place ; T, a bench clamp ; A, 
brass plate on which to cut. 

The great advantage in this construction is the pin and 
plug moving (up and down) vertically without turning or twist- 
ing in the tube or cyhnder more than the fractional ease of the 
slots in which the studs work. The plug being fitted nicely to 
the cylinder, and the pin fixed into it, and the nut working 
nicely in the collar, gives a firmness not to be obtained in 
machines in which the pin turns. The pitch of the screw is 
25, therefore a quarter turn of the nut gives the looth part, 
and an eighth turn the 200th part of an inch. 




76 



MISCELLANEOUS TOOLS, 



The cutter is a spokeshave with the ends turned straight 
and fitted into handles. The hollow, or under side, on the plate 
is used, the face of the plate being very flat and straight. The 
inventor of this machine prefers the under side of a cutter hollow, 
not flat, as recommended by many. There is less adhesive 
resistance, and no sHpping, as with the perfectly flat surface. 



Hints on the Microscope. — A mechanical stage is a sine 
qua non, and plenty of room beneath it for the illuminating 
apparatus. This stage should not be thicker than the |th o-f 
an inch, a mere plate with a wide hole, say 2 in. square, the 
milled hands and tangent screws being all placed behind the 
frame, easy to get at, and out of the way of the objects. 

This form does not admit of a circular motion, but we have 
not yet learnt the real value of such a motion, while the advan- 
tages of a thin stage are unspeakable. 

A Coddington lens, or an eye-piece on Kelner's principle, 
makes a good condenser, and only cone eye-pieces are worth 
using ; if you desire higher magnification, either get a higher 
power or lengthen your tubes. 

An economic condenser made by an amateur microscopist 
is shown in the following sketches : — 



Fig. 



I. — A, spot-lens, about 



1-in. 




0' 



H 



Fig. I. 



focus ; B, achromatic 
spot-lens, about i ^- 
in focus, placed 
at about the same 
distance as in a 
Kelner eye-piece,in 
a tube C, screwed 
in a flat ring of 

j> metal D, which is 

supported on a flat 

Q"^ plate G, secured 

^^ by a holdfast E, 
allowing room be- 
tween for a dia- 
phragm F, to re- 
volve freely on its 
axis, which is done 
H is 



by a screw passing through a holdfast into the plate G ; 
a tube |-in. long for carrying polariscope. 



INSTRUMENTS, AND PROCESSES. 



11 




Fig. 2. — Diaphragm. — A, for direct light ; B, for difficult 
test-objects; C, dark- 
ground illuminator ; 
D, small aperture, 
with shutter E, hav- 
ing a small hole in 
it. The features 
presented by this 
condenser are that 
it is applicable for 
both high and low 
powers, can be used 
by merely shding it 
into a tube under 
the stage, and never 
need be removed 
except for cleaning. 
For a micrometer, 
the following plan. Fig. 2. 

which any one can adopt, and requires no apparatus, is quite 
effective. 

Find the exact size of your field by looking at a footrule 
laid beside your stage with the one eye, while the other is 
applied to the pipe ; say it gives i ft. Now put the rule 
on the stage, and see how many divisions of an inch fill the 
field ; suppose it is |th in. in this assumed case, this object- 
glass, with the same length of tube, will magnify 96 linear, 
therefore all objects view^ed will be increased to that extent. 

Your instrument must be steady, the fine adjustment very 
fine, the spring very light, and the tube into which the object- 
glass is screwed, and which the adjustment moves, very true, 
and also very easy to lift, so that a coarse hand may neither 
damage the instrument nor object, and each turn ought to raise 
or depress it i-iooth of an inch, and so become a micrometer to 
measure depth. 

For a camera lucida, get two bits of neutral-tinted glass, and 
place them at an angle of 45° before the eye-lens. A little 
practice will enable you thus to use the binocator, and the ease 
to the eyes is immense. 

For polariscope, use a short white Nicol's prism, set so as to 
turn in a tube, and to which tube you can ^crew the object-^lass. 



78 MISCELLANEOUS TOOLS, 

A number of large squares (i6 or 20, -^ size) such as we cover 
objects with, form the best analyser. The polariscope is, how- 
ever, except in the hands of the chemist, pretty much a toy. 

It is a great mistake to have slides in any numbers ; have 
many compressioriums, lots of bottles and small tanks, and 
eschew diatomacae valves. Wherever you go, carry a nail or 
two and an old lucifer-box, a walking-stick and a bit of string ; 
tie a vial to the stick, and dip from top, bottom, and middle of 
every permanent water-hole ; when you find a small insect, put 
him in the box. Your walks will be all pleasure, and your 
evenings both pleasure and instruction. Make for yourself all 
your apparatus ; never mind the polishing, but make all good 
and true as to the brass, &c. ; put all the polish on the glasses, and 
begin with a 2-in. and a |^-in. ; the glass of moderate angle is 
much preferable to the ground 1708 lenses. These latter can- 
not be illuminated by annular condensers, and thus the prettiest 
and pleasantest way of viewing an object is lost. The ** celia " 
of the Feloscalaria ornata, for instance. 

Keep in your small tanks a few roots of Zitella, and Valis- 
neria : both are good for the infusoria, and charming objects in 
themselves. From the air, ground, river, pond, or sea, get 
your objects ; remember that slides once seen become tire- 
some. 

Mathematical Instruments, &c. — All polished steel 
instruments are best kept from rust by enclosure in wool. 
The high conducting power of metal causes easy condensation 
of moisture (the cause of rust) ; wool is a good non-conductor 
of heat or cold. 

Weather- Glass. — Various experimental barometers have 
from time to time been constructed, all with the view of com- 
bining economy with simplicity in a greater degree than is 
obtained in the ordinary weather-glasses of commerce. 

A simple barometer may be made as follows : — 

A wide-mouthed glass bottle is filled with ordinary drinking 
water up to the point indicated by the letter A ; into this is 
dipped an inverted clean oil-flask, the extremity of the neck 
being allowed to dip just below the surface of the water. 

The flask should be inverted quite empty during wet weather, 
and as long as the atmosphere remains in a stormy condition 
no change in the water takes place ; but immediately the 



CEMENTS AND GLUES. 



79 





,l\ 


e:^3=£= 




b%-i^-^ 


: —-_ -^——. 


ly^^= 


-■:=-,=j€-^i=^.^:^ 





weather becomes finer, the water will rise in the neck of the 
inverted oil-flask, and if a continuance of 
fine weather be probable, will rise to the 
point indicated by letter B. 

This simple contrivance gives sure 
and early warning of the approach of 
rain. 

The principle upon which this little 
weather-glass ticts is exactly similar to 
that of the ordinary mercury barometer, 
the rise and fall of the water due to the 
respective increase or decrease of atmo- 
spheric pressure. 

By dividing the neck AB into six or 
eight divisions with the aid of a diamond 
or piece of flint, and then marking the 
lines so cut with ink, an approximate 
graduation of degrees of pressure may 
easily be obtained. 

Cements and Glue. — Below are given a variety of cements 
to join anything from a millband to a knife-handle. The 
relative proportions are given in each case, and the directions 
for mixture and application must be strictly followed. 

Cement to join Leather or India-Rubber. — To unite pieces 
of leather or india-rubber, use either of the following : — 

One ounce of caoutchouc cut in thin slices, and placed 
in a tinned sheet-iron vessel, with six or seven ounces of 
sulphide of carbon ; the vessel is then to be placed in a water- 
tank, previously heated to about 86^ Fahr. To prevent the 
solution from becoming thick and unmanageable, mix with a 
solution consisting of spirits of turpentine, in which half an 
ounce of caoutchouc in shreds has been dissolved over a slow 
fire, and then a quarter of an ounce of powdered resin, from an 
ounce and a half to two ounces of turpentine being afterwards 
stirred in in small quantities. 

Put a small quantity of virgin or native rubber, cut into 
shreds, into a wide-mouthed bottle, and pour over it benzine 
until the bottle is about three-quarters full. The rubber will, 
if often shaken, in a few days assume the consistency of honey, 
with a thick sediment at the bottom. If not thoroughly dissolved 



8o CEMENTS AND GLUES. 

more benzine must be added. The benzine must be of the best 
quahty, and free from oil. Except when using, the bottle con- 
taining this cement must be kept well corked. 

This cement dries in a very short time, and three coats 
applied in the usual manner will serve to unite anything either 
in leather or rubber. 

Dissolve gutta-percha (i oz.) in bisulphide of carbon (6 oz). 
Apply the solution to both surfaces to be joined, allow to 
dry, which will take a few minutes ; then place a hot iron 
near enough to just melt the gutta-percha on both surfaces ; 
immediately press them well together, through rollers or under 
pressure. Leather fastened in this way does not need sewing. 
[A hose-pipe can only be joined in one way — the broken part 
cut out, the edges made square, a short piece of brass tube 
— fitting the hose tightly — inserted, and the two ends brought 
together over it, and bound tightly with copper wire]. 

Another excellent cement for millbands, &c., is — To 4 oz. of 
bisulphide of carbon add \ oz. india-rubber, and \ oz. gutta- 
percha, cut in shreds ; place the whole in a half-pint bottle, 
w^ell corked. It will dissolve without heat in about 12 hours, 
and be ready for use. The parts to be joined must be thinly 
coated with the solution, and allowed a few minutes to dry ; 
then heat to melting, very quickly place together, and well 
hammer the air-bubbles out ; the joint will be nearly solid, and 
has been proved perfect. The parts to be joined should be 
thinned down a little, so as to make an even splice ; and the 
vessel containing the cement kept, tightly corked, in a cool 
place. 

Cement for Tracings. — Take i oz. of isinglass glue, and 
I oz. of glue made of parchment, 2 drachms each of sugar- 
candy and gum tragacanth. Add i oz. of water, and boil 
together till mixed ; when cold, form into little cakes. When 
to be applied, the glue may be wetted on a bit of sponge, and 
rubbed on the edges to be cemented ; they will readily cohere 
on pressure. 

Cement for Uniting Wood with Metals, Glass, Stone, 

&c. — Dissolve glue in boiling water, and make it of the same 
consistence as cabinetmaker's glue ; then add, while stirring, 
a sufficient quantity of wood ashes to produce a varnish-like 
mixture. While hot^ the surfaces to be united must be covered 



CEMENTS AND GLUES, 8i 

or coated with this glue compound, and firmly pressed together. 
When cold, the joint will be strong, and the article ready for 
use. 

Chemical Cement. — By melting together 2 lbs. of wax, 10 
lbs. of resin, mixed with 4 oz. of plaster of Paris, and 2 lbs. of 
red ochre, an excellent cement can be made to serve for 
chemical and electrical apparatus. 

Cement for Fixing Metal, Glass, Porcelain, &c. — The 

following is a simple and useful cement, having also the 
additional recommendation of cheapness. Make a tolerably 
strong solution of alum, stir into it plaster of Paris, until the 
liquid becomes of the consistency of cream, and use while in a 
liquid state. 

This cement may be used for fastening brasses on lamps, &c. 

Cement for Mother-of-Pearl, &c. — In 60 parts of water 
dissolve 4 parts of white glue and 2 parts of isinglass ; then 
strain and evaporate until its volume is reduced to ^th ; add 
y^th part of gum mastic dissolved in i part of alcohol, and 2 
parts of zinc. When required for use, it requires to be warmed 
and shaken. 

Glue that will Resist the Action of Water. — Boil i lb. 

of common glue in 2 quarts of skimmed milk. 

Cement for Glass that will Resist Heat. — Equal parts of 
wheat, flour, glass, and chalk, finely powdered ; to this mix- 
ture add half as much brick dust, and a little scraped lint in 
the white of eggs. 

Cement for Aquaria. — Any of tlie following cements may 
be used to prevent leakage : — 

1. I pint fine white sand, i pint litharge, ^ds of a gill of 
finely-powdered resin. Mix well, and keep in a corked bottle. 
When used, it requires to be mixed with boiled oil and driers, 
until of the consistency of putty. Do this mixing in quanti- 
ties just sufficient for each piece of glass, as it dries very 
quickly. 

2. Boiled oil, red and white lead, and litharge mixed together, 
and spread on a flannel, and placed on the joints. 

3. 2 oz. benice turpentine, and solution of glue i lb. Boil 
these together, stirring the whole time until perfectly mixed. 

F 



82 CEMENTS AND GLUES, 

This cement sets slowly, and the joints require to be kept 
together for two days. 

4. Collins' cement, which is elastic, waterproof, and harm- 
less, dries very quickly. When used, it should be cut up into 
small pieces about the size of a pea, and laid along the joint ; a 
heated wire then being applied, the cement will run into a 
continuous strip along the joint. • 

Fire and Water-Proof Cements. — i. Take 2 parts of 
finely- sifted, unoxidised iron filings, mix with i part of per- 
fectly dry and finely-powdered loam, and knead the mixture 
with strong vinegar until a perfectly homogeneous plastic mass 
is formed, when the cement is ready for use. It must be made 
as wanted, for it quickly hardens, and, once set, is never fit for 
use again. 

2. A very excellent cement for smaller articles is made thus : 
— Soak 2 drachms of cut isinglass in 2 oz. of water for 
twenty-four hours ; boil to i oz., add spirit of wine i oz., and 
strain through linen. Mix this, while hot, with a solution of i 
drachm of mastic, in i oz. of spirit of wine, and triturate with 
^ drachm of powdered gum ammoniac, till perfectly homo- 
geneous. 

Postage-Stamp Gum. — The gum used for stamps is what 
is called British gum, which is made from starch ; its proper 
name is dextrine QaHioOjo ; it is usually made by heating 
commercial starch suddenly to 320° ; anhydrous starch requires 
a temperature of 400°, and maintaining it at this heat for some 
time. The soluble product is dextrine or British gum, or the 
leiogomme of the French. Dextrine may be prepared on a large 
scale, of a much lighter colour, by the following process : — 
10 parts starch mixed wdth 3 of water, containing i-i5oth 
of its weight of nitric acid, allowing the mixture to dry 
spontaneously, and then spreading it upon shelves to the depth 
of i^ in., and heating for an hour or hour and a half to 
above 240°. 

Cement for Hot-Water Pipes. — Ram on to the flange a few 
strands of tarred rope, and fill up with iron boring cement, and 
ram in well. 

Cement for Joining Steam Pipes.— Boiled linseed oil, 
litharge and whitelead, mixed up to a proper consistence, 



VARNISHES AND LACQUERS, 83 



and applied to each side of a piece of flannel, linen, or even 
pasteboard ; and then placed between the pieces before they 
are brought home, as it is called, or joined. The cement is 
useful in joining broken stones, seams of water cisterns, &c. 

Cement for Joining Steam Joints. — Sal ammoniac, 2 oz. ; 
sublimed sulphur, i oz. ; fine cast-iron turnings, i lb. ; mix in 
a mortar, and keep dry. When to be used, mix with twenty 
times its quantity of clean iron turnings or filings, and triturate 
the whole in a mortar. Then wet with water until of a con- 
venient consistence. 

Red Putty for Steam Joints. — Stiff whitelead worked well 
in redlead powder. 

Durable Cement. — Common clay well dried and powdered, 
then mixed with boiled linseed oil : it will last years. Mix 
ground whitelead with as much powdered redlead as will 
make it the consistency of putty. Mix equal weights of red- 
lead and whitelead with boiled linseed oil to a proper con- 
sistence. These three cements mend stones well, however 
large. 

Liquid Glue. — White glue, 16 oz. ; dry whitelead, 4 oz. ; 
soft water, 2 pints ; alcohol, 4 oz. : stir together, and bottle 
while hot. 

Varnishes. — In accordance with the nature of the solvent, 
varnishes are called spirit varnishes, turpentine or volatile oil 
varnishes, or fat oil varnishes. The first of these, whose 
solvent is sometimes ether or chloroform, but more commonly 
spirits of wine or wood spirit, dry off rapidly. These are very 
thin in coat when dry, and are best suited for paper, fans, or 
any very fine work requiring perfect transparency in the 
varnishes. Volatile oil varnishes, in which the solvents are 
spirits of turpentine, or coal naphtha, or the like, are those 
mostly employed by the oil painter. What is called " French 
varnishing," so much employed upon the wood of furniture, &c., 
consists in the application of alternate films of lac varnish 
and of linseed oil, with constant and sufficient friction to 
polish the compound film of spirito-fat oil varnish as soon as it' 
has become thick enough to afford a glossy surface, the total 
thickness being exceedingly small. The method of varnishing 
employed by the carriage-builder for his finest work is the very 



84 VARNISHES AND LACQUERS. 

opposite of this. Over his last coat of paint he lays on coat after 
coat of copal or dammar varnish, until he has got a consider- 
able thickness, often nearly YO^th of an inch. When this 
to its full depth has got hard and perfectly vitreous in the 
warmth of the ^' varnishing-room," the whole surface is literally 
ground off with pumice-stone and water until a perfect form, as 
to contour, and a perfect superficies have been procured, when 
the glossy face of the varnish is then poUshed by putty powder, 
chamois skins, the hand, &c., just as a plate of looking-glass 
is polished. 

Black Japan Varnish. — i. Boiled oil, i gallon; amber, 
8 oz.j asphaltum, 3 oz.; oil of turpentine, as much as will 
reduce it to the thinness required. 

2. Take pitch 50 lbs., dark gum amber 8 lbs., melt this, and 
add linseed oil 12 gallons. Boil this, and add 10 lbs. more 
gum amber, previously melted and boiled with 2 gallons of 
linseed oil, 7 lbs. each of litharge and redlead, and boil for two 
hours, or until a little of the mass can be rolled into pills ; then 
withdraw the fire and thin the varnish as required for use with 
turpentine. 

Varnish for Coloured Drawings. — Take 4 oz. of spirits 
of turpentine, and mix with 2 oz. of Canada balsam. Size 
the picture with a solution of isinglass in water. When this is 
dry, lay on the varnish with a camel's hair brush. 

Varnish for Paintings. — Take mastic, 6 oz. ; pure tur- 
pentine, \ oz.; camphor, 2 drachms ; spirits of turpentine, 
19 oz.; add first the camphor to the turpentine. The mixture 
is made in a water-bath ; when the solution is effected, add 
the mastic and the spirits of turpentine near the end of the 
operation ; filter through a cotton cloth. 

Varnish for Glass. — Dissolve gum adragant in the white of 
eggs, beat up well, and lay it on the glass with a soft brush. 
The gum will take about twenty-four hours to dissolve. 

Aniline Black Varnish. — The following is an approved 
Parisian varnish : — In a litre of alcohol, 12 grammes of aniline 
blue, 3 grammes of fuchsine, and 8 grammes of naphthaline 
yellow are dissolved. The whole is dissolved by agitation in 
less than twelve hours. One application renders an object 



VARNISHES AND LACQUERS. 85 

ebony black. The varnish can be filtered, and will never 
deposit afterwards. 

Paper Varnish. — Below we give an excellent method of 
varnishing paper. First prepare the following varnish : — Pound 
very fine 4 oz. white sealing-wax, and after having sifted it 
through a lawn sieve, dissolve it in 2 oz. of alcohol. To 
dissolve, the ingredients must be put into a large bottle, and 
be shaken frequently during the space of forty-eight hours. 
Give your work two coats of a size made by boiling parchment 
cuttings in clear water, observing to do it quickly. When 
dry, apply the above varnish. 

To Varnish Earefied Air Balloons. — With regard to 
rarefied air machines, first soak the cloth in a solution of sal 
ammoniac and common size, using i lb. of each to every 
gallon of water ; and when the cloth is quite dry, paint it 
over on the inside with some earthy colour, and strong size or 
glue ; when this paint has dried perfectly, it will then be proper 
to cover it with oily varnish, which might dry before it could 
penetrate quite through the cloth. Simple drying linseed oil 
will answer the purpose as well as any, provided it be not very 
fluid. 

Copal Varnish. — One of the best preparations for this 
varnish is the following : — Dissolve i oz. of camphor in i quart 
of alcohol, put it in a circular glass, and add 8 oz. of copal in 
small pieces ; set it in a sand heat until it is dissolv^ed, so 
regulated that the bubbles may be counted as they rise from 
the bottom, and continue the same heat until the solution is 
completed. Camphor acts more powerfully upon copal than 
any substance yet tried. If copal be finely powdered, and 
mixed with a small quantity of camphor, in a mortar, the 
whole soon becomes one tough, coherent mass. 

Colourless Varnish with Copal. — To prepare this var- 
nish, which can be applied to wood, metals, &c., the copal 
must be picked ; each piece is broken, and a drop of rosemary 
oil poured on it. Those pieces which oh contact with the oil 
become soft are the ones used. The pieces being selected, 
they are ground and passed through a sieve, being reduced to 
a fine powder. It is then placed in a glass, and a correspond- 
ing volume of rosemary oil poured over it ; the mixture is then 
stirred for a few minutes until it is transformed into a thick 



86 VARNISHES AND LACQUERS, 

liquor. It is then left to rest for two hours, when a few drops 
of rectified alcohol is added and intimately mixed. Repeat 
the operation until the varnish is of a sufficient consistency ; 
leave to rest for a few days, and decant and clear. 

Varnish for Perforated Zinc. — i dwt. of Canada balsam, 
thinned with spirits of turpentine until it is the consistency of 
milk. Then with a camel's hair flat brush sparingly varnish 
the perforated zinc. It does not require to be made warm, as 
articles do which have to be lacquered. It is this varnish which 
is usually made use of in fixing and covering the silvered parts 
of clock faces. 

Wood . Varnish to Resist Boiling Water. — Boil 3 lbs. 
of linseed oil in an untinned copper vessel. While boiling, 
suspend in the oil a bag containing 6 oz. of minium and 10 oz. 
litharge, both finely powdered, so that it will not touch the 
bottom of the vessel. When the oil has acquired a deep-brown 
colour, take out the bag and replace it by one containing a 
small piece of garlic. Melt 2 lbs. of yellow amber with 4 oz. 
of linseed oil, and throw into the vessel. Let the whole boil 
for about four and a half minutes, stirring well. After it has 
rested awhile, decant it ; and when cold, pour it into stoppered 
bottles. 

The wood having received the necessary colour, and having 
been properly polished, four coats of the above should be laid 
on with a fine sponge. 

A method of coating wood with a varnish as hard as stone 
has been recently introduced : the ingredients are — 40 parts 
of chalk, 40 of resin, 4 of linseed oil, to be melted together in 
an iron pot. i part of native oxide of copper, and i of sulphuric 
acid, are then to be added, after which the composition is 
ready for use. It is applied hot to the wood with a brush, in 
the same way as paint, and as before observed, becomes" 
exceedingly hard on drying. 

Varnish for Wood Patterns. — 3 oz. of shellac, \\ oz. of 
resin, dissolved in a pint and a half of wood naphtha. 

French Polish. — Any of the following receipts for French 
polish may be used: — i. Shellac, i lb. ; naphtha, 2 lbs. ; 
dragon's blood, 3 oz. 2. Shellac, 15 oz. ; powdered mastic, 
\ oz. ; sandarac, \ oz. ; copal varnish, 5 oz. ; methy- 
lated spirit, 2 lbs. 3. Shellac, 22 oz. ; spirit of wine, 4 pints ; 



VARNISHES AND LACQUERS, 87 

cod-liver oil, 2 oz. 4. Spirit of wine or naphtha, i pint ; 
gum, \ oz. ; shellac, 3 oz. ; dissolve with a gentle heat, and 
add 2 oz. of oil of sweet almonds. 5. Shellac, i oz. ; oxalic 
acid, I drachm ; naphtha, 4 oz. ; dissolve, and then add \ oz. of 
linseed oil. 6. i J lb. shellac to i gallon spirit is a good pro- 
portion ; naphtha should be used only for coarse work. 
Methylated spirit is much preferable. No better polish is 
made than that with shellac alone, but in finishing, let the 
work, if small, and can be conveniently done, be wai^med. 

Varnish for Violins. — The varnish most used for violins is 
what is called a " fat '^ or oil varnish, made with amber. This 
is the most insoluble of gum resins, and, in its natural state, 
soluble only in chloroform. It contains an essential oil, oil of 
amber, and, until deprived of this by the process of melting, 
cannot be mixed or dissolved in spirits of turpentine. To form 
it into a varnish for violins, melt it very carefully in a sand- 
bath. A small iron saucepan half-filled with sand, in which a 
small thin cup is embedded to contain the amber, which should 
be coarsely powdered, will answer the purpose. If black 
smoke comes from the melting amber, the heat is too great — 
the amber is burning ; the right heat must be found by trial, 
it will be pretty well marked by the smoke or vapour being 
light- coloured or white. This indicates the evaporating oil of 
amber, which may be condensed if a retort and receiver is used. 
The vapour has a very powerful penetrating smell. A small 
quantity of amber will suffice, say i drachm, to make varnish 
for two or three violins. The amber, when sufficiently melted, 
will, when cool, be of a dark-brown colour, and in small brittle 
flakes. In this state put it into a small bottle with camphine 
(the best spirit of turpentine procurable), sufficient for solution 
(about four times the bulk of the prepared amber). Allow the 
mixture to remain a day or two, with occasional shaking ; then 
add best drying linseed oil, equal to \th. part of camphine. 
Size your violin, and get the grain of the wood thoroughly 
smooth, and apply the varnish with your finger on a warm 
sunny day, exposing the violin to the sun and air. A number 
of coats will be required, but a second should not be put on 
until the first is dry. Colouring-matter may be rubbed up with 
a palette knife, and some of the varnish, but there is great 
difficulty in laying the colour on smoothly. 



88 VARNISHES AND LACQUERS. 

Friction Polish. — A good polish for iron or steel rotating 
in the lathe is made of fine emery and olive, sperm, or neat's 
foot oil. Apply by lead or wood grinders, screwed together. 

Soft Varnish. — For a good soft varnish, take linseed oil, 
4 oz. ; and | oz. each of gum benzoin and white wax. Boil to 
two-thirds. 

Dryers. — Grind i lb. of white copperas, i lb. sugar of lead, 
and 2 lbs. whitelead with boiled linseed oil. Boiled or drying 
oil is linseed oil mixed with powdered litharge, and heated till 
it becomes thick. A " pale '^ drying oil is obtained by mixing 
with linseed oil sufficient dry sulphate of lead to form a milky 
liquid, and shaking it repeatedly for some days, letting it stand 
exposed to the light. When it has become quite clear, it may 
be poured off from the dregs. The sulphate of lead, when 
washed from the mucilage, may be again used for the same 
purpose. 

Vehicle for Colour. — A good vehicle for colour is made by 
boiling shellac and borax in water. This solution may be 
used as a varnish, and, mixed with lampblack, forms an ink 
which will resist almost any acid. 

Substitute for Brewer's Pitch. — Coat twice the inside of 
a barrel with a solution of \ lb. of rosin, 2 oz. of shellac, 2 lbs. of 
turpentine, and \ oz. of yellow wax in i quart of strong alcohol. 
After the complete drying of the second coat, give a last coat 
by applying a solution of i lb. of shellac in i quart of strong 
alcohol. This varnish will perfectly cover up the pores, and 
does not crack off or impart a foreign taste to the beer. 

Lacquers. — Lacquers are used upon polished metals and 
wood, to impart the appearance of gold. As they are wanted 
of different depths and shades of colours, it is best to keep a 
concentrated solution of each colouring ingredient ready, so 
that it may at any time be added to produce any desired tint. 
Lacquer should always stand till it is quite firm before it is 
used. 

1. Deep Golden-coloured Lacquer. — Seed lac, 3 oz. ; tur- 
meric, I oz. ; dragon's blood, \ oz. ; alcohol, i pint. Digest 
for a week, frequently shaking. Decant and filter. 

2. Gold-coloured Lacquer, — Ground turmeric, i lb. ; gam- 



VARNISHES AND LACQUERS. 89 

boge, i|- oz. ; gum sandarac, 3^^ lbs. ; shellac, | lb. (all in 
powder); rectified spirits of wine, 2 gallons. Dissolve, strain, 
and add i pint of turpentine varnish. 

3. Red-coloured Lacquer, — Spanish anatto, 3 lbs. ; dragon's 
blood, I lb. ; gum sandarac, '^\ lbs. ; rectified spirits, 2 gallons ; 
turpentine varnish, i quart. Dissolve and mix as the last. 

4. Pale Brass-coloured Lacquer, — Gamboge, cut small, i oz.; 
cape aloes, ditto, 3 oz. ; pale shellac, i lb. ; rectified spirits, 
2 gallons. Dissolve and mix as No. 2. 

5. Seed lac, dragon's blood, anatto, and gamboge, of each 
\ lb. ; saffron, i oz. ; rectified spirits of wine, i o pints. Dis- 
solve and mix as No. 2. 

Excellent lacquers are also made by the following receipts : — 

1. Gold Lacquer, — Put into a clean 4-gallon tin i lb. ground 
turmeric, \\ oz. of powdered gamboge, '^\ oz. of powdered 
gum sandarac, | lb. of shellac, and 2 gallons of spirits of wine. 
After being agitated, dissolved, and strained, add i pint of 
turpentine varnish, well mixed. 

2. Red Lacquer, — 2 gallons of spirits of wine, i lb. of dragon's 
blood, 3 lbs. of Spanish anatto, \\ lbs. of gum sandarac, 
2 pints of turpentine. Made as No. i lacquer. 

3. Pale Brass Lacquer. — 2 gallons of spirits of wine, 3 oz. of 
cape aloes, cut small, i lb. of fine pale shellac, i oz, of gam- 
boge, cut small, no turpentine varnish. Made exactly as before. 

Those who make lacquers frequently want some paler, and 
some darker, and sometimes inclining more to the particular 
tint of certain of the component ingredients. Therefore, if 
a 4-0Z. vial of a strong solution of each ingredient be prepared, 
a lacquer of any tint can be procured at any time. 

4. Pale Tin Lacquer. — Strongest alcohol, 4 oz. ; powdered 
turmeric, 2 drachms ; hay saffron, i scruple ; dragon's blood 
in powder, 2 scruples ; red saunders, \ scruple. Infuse this 
mixture in the cold for forty-eight hours, pour off the clear, and 
strain the rest ; then add powdered shellac, \ oz. ; san- 
darac, I drachm ; mastic, i drachm ; Canada balsam, i 
drachm. Dissolve this in the cold by frequent agitation, laying 
the bottle on its side, to present a greater surface to the alcohol. 
When dissolved, add 40 drops of spirits of turpentine. 

5. Deep Gold Lacquer, — Strongest alcohol, 4 oz. ; Spanish 
anatto, 8 grains ; powdered turmeric, 2 drachms ; red 
saunders, 12 grains. Infuse and add shellac, &c., as to the 



90 SOLDERS AND SOLDERING. 

pale tin lacquer ; and when dissolved, add 30 drops of spirits 
of tua'pentine. 

6. Another Gold Lacquer, — Seed lac, 6 oz. ; amber gum, 
guttae, 2 oz. each ; extract of red sandal-wood in water, 24 
grains ; dragon's blood, 60 grains ; oriental saffron, 36 grains ; 
pounded glass, 4 oz. ; pure alcohol, 36 oz. Grind the amber, the 
seed lac, gum guttae, and dragon's blood on a piece of por- 
phyry ; then mix them with the pounded glass, and add the 
alcohol, after forming with it an infusion of the saffron and an 
extract of the sandal-wood. Then grind all thoroughly. The 
metal articles destined to be covered by this varnish are heated, 
and such small articles as will admit of it, as small cases, watch- 
keys, &c., are immersed in packets. The tint of the varnish 
may be varied by modifying the doses of the colouring substances. 

Before Lacquering Brass boil it in a solution of potash 
and soda, after which dip them in aquafortis, 3 parts water. 
Then wash them in two different waters, and rub them through 
sawdust. Then place on a gas stove. When warm, brush and 
put the lacquer on. After this operation is complete, the work 
is put back on the stove with a piece of brown paper over it. 
You can burnish or pick out, as you please. 

Good Lacquer for Brass. — Seed lac, 6 oz. ; amber or 
copal, 2 oz. ; best alcohol, 4 gallons ; pulverised glass, 4 oz. ; 
dragon's blood, 40 grains ; extract of red sandal-wood, obtained 
by water, 30 grains. 

Pale Lacquer for Tin Plate. — Best alcohol, 8 oz. ; 
turmeric, 4 drachms ; hay saffron, 2 scruples ; dragon's blood, 
4 scruples ; red saunders, i scruple ; shellac, i oz. ; gum 
sandarac, 2 drachms ; gum mastic, 2 drachms ; Canada 
balsam, 2 drachms ; when dissolved, add spirits of turpentine, 
80 drops. 

Lacquer for Philosophical Instruments. — Alcohol, 80 
oz. ; gum gutta, 3 oz. ; gum sandarac, 8 oz ; gum elemi, 
8 oz. ; dragon's blood, 4 oz. ; seed lac, 4 oz. ; terra merita, 3 
oz. ; saffron, 8 grains ; pulverised glass, 1 2 oz. 

Solders and Soldering. — Soft Solders. — Tin and lead 
in equal parts. Easier of fusion still is tin, lead, and bis- 
muth, in equal parts ; or i or 2 bismuth, i lead, and i tin, 
easier still. For soft soldering brass, tin-foil makes a fine 



SOLDERS AND SOLDERING, 91 

juncture, applied between the joints, care being taken to avoid 
too much heat. This is most excellent for fine brass-work. 
The tin-foil must be moistened in a strong solution of sal- 
ammoniac. 

Plumber's Solder. — i part bismuth, 5 parts lead, and 
3 parts tin, forms a compound of great importance in the 
arts. 

Brass Solder for Iron. — Melt the plates of brass between the 
pieces that are to be joined. When the w^ork is very fine, the 
parts to be brazed should be covered with powdered borax, 
melted with water, so that it may mix with the brass powder 
which is added to it. Expose the piece to a clear fire in such 
a manner that it shall not touch the coals, and let it remain 
until the brass begins to run. 

Silver Solder for Jewellers. — Take 20 dwt. of brass, 
2 dwt. of copper, and 38 dwt. of fine silver, and melt them 
together. 

Silver Solder for Plating. — Take \ oz. of pure silver and 
5 pennyweights of brass, and melt them together. 

Soldering Steel and Iron without heat. — Take \ oz 
of thirid acid, \ oz. of spelter, \ oz. of bismuth, and \ oz. of nitric 
acid. Put them all into the thirid acid ; after well mixing, 
touch each part required to be soldered with the mixture, and 
put them together. 

Solder for Tinware. — An excellent solder for tinware 
can be made from the lining of tea-chests. 

Soldering for Leaden Gas- Pipes. — The blowpipe is not 
absolutely necessary, as the flame of the candle gives heat 
sufficient for the purpose by itself : prepare the joint in the 
usual way, then grease and sprinkle on a little powdered rosin. 
Now apply the flame of the candle, and touch with a strip of 
fine solder : as soon as the joint is sufficiently heated, the 
solder will flow easily. One candle will be sufficient for the 
smaller sizes of pipe ; but by using two or more candles, 
joints may be made in this way up to i in. ox i\ in. The solder 
must be fine, such as tinners use ; poured out in thin strips, 
and cut by the shears \ in. broad. In ga&-pipes of what is 
called composition metal the blowpipe is absolutely necessary ; 



92 METALS AND METAL-WORKING. 

and, in fact, a blowpipe is most useful, and used in directing 
the flame round the pipe or to a required spot, and keeping up 
a continuous heat. 

Blowpipe Joints are thus made : — Slightly taper one end of 
the pipe, and open the other end for it to fit into ; clean the 
inside of the opened length, and the outside of the tapered end. 
Grease the same with common tallow, and sprinkle a little 
powdered rosin on it. Now with lo-in. blowpipe in the mouth, 
and rushes or spirit lamp held in the left hand, and a thin strip 
of soft solder in the right, gently heat the pipe before applying 
the solder. This solder should be composed of 3 parts fine 
tin, to 2 of lead. A small portion of bismuth will make it flow 
more easily. 

Soldering, Hard, — One of the most common is that of 
silver soldering ; it is composed of silver 2 parts, brass i part 
(common pins are the best). The silver is melted first, the 
brass then added and well melted together ; it is then milled 
to the thickness of stout paper. 

The work that requires to be soldered should be scraped 
clean and bound together with iron binding- wire. «* 

A piece of lump borax is next rubbed with a little clean 
water on a piece of slate to the consistency of cream : the work 
should be covered with this by means of a small pencil, especially 
the parts to be soldered ; the solder is then cut into very small 
pieces and laid across the joint with the pencil also ; the work 
is then put on a piece of charcoal or bundle of iron wires, and 
gradually heated till the solder melts (by means of the blow- 
pipe and gas). For rings, a piece of solder is passed between 
the join, and served as above (be careful of the stones, they 
must not be made red hot). Gold is generally soldered by 
gold of an inferior quality, as 22 carat soldered with 18 carat, 
1 8 carat with 1 6 carat, &c. After soldering the binding-wire 
is removed, and the work boiled in nitric or sulphuric acid 
pickle (i part acid, 10 parts water), and finished accordingly. 
It requires much practice to become master of the blowpipe. 

Brass Melting. — The best method of melting brass is in 
a plumbago crucible. The best furnaces are built of fire-brick, 
open at the top, with an opening in the upper part of the 
back, connecting the furnace with the chimney, and another 
larger opening in the front, below the grate bars. A good 



METALS AND METAL-WORKING, 93 

practical furnace may be made 12 in. square inside, 18 in. 
deep to grate, 12 in. below grate for cinders and air-passage, 
chimney opening 4^ by 3, and 3 in. from top of furnace. 
This furnace is large enough for a No. 25 crucible, which will 
melt about 50 lbs. of brass. 

To avoid Air-holes or Flaws in Brass Castings.— 
The theory of their formation is as follows : — Melted metal is 
more bulky than cold metal, and as the outside of castings cool 
first, it follows that the shrinking must take place within. The 
so-called air-holes are in reality not air-holes at all, but cavities 
formed by the shrinking of the metal. To avoid them, endea- 
vour to equalise the patterns by coring, &c. If such is not to 
be done, run from the thickest part with a heavy runner. This 
process will tend to keep all in a fluid state until the outer 
portions have set, and so fill the cavities as they form. 

Bending Brass Tubes. — Brass tubes are best joined by 
brazing up with melted brass. Tubes for musical instru- 
ments are bent by first filling them with lead, which, as soon 
as they have been brought to the required shape, is easily- 
melted out again. 

Brass Pickling or Brightening. — In order to remove 
the grease and dirt that may have accumulated during the 
process of fitting, the work should be placed in a red-hot 
muffle, or over an open fire ; unless it be soft soldered, when of 
course it must be annealed before being fitted. If that be the 
case, or if the work have ornamental surfaces, it should be 
boiled in potash lye. When this is done, immerse it in a bath 
composed of diluted sulphuric or nitric acid in the proportions 
of I part acid to 3 of water. Allow the work to remain in 
this solution for from one to two hours, according to the 
strength of the acid ; then rinse with water, and scour with 
sand, using a common scrubbing-brush ; then wash well. To 
make the pickling-bath, dissolve 2 parts of zinc in 6 parts 
of nitric acid of 36° Baume, in a porcelain vessel, then add 
to the mixture 1 6 parts of nitric acid and 1 6 parts of sulphuric 
acid. Boil this liquid, and while boiling, plunge the work 
into it for about half a minute, until the nitrous vapour 
ceasing, the surface becomes uniform. Then rinse it well 
in clear water, to remove the acid. Should the work have 



94 METALS AND METAL-WORKING. 

assumed a greyish-yellow tint, this may 6e removed by 
immersing the work for a short time in nitric acid. It 
should then be rinsed in a weak solution of potash, and 
covered with beech or boxwood sawdust, and afterwards rubbed 
until quite dry ; after this it should be lacquered, to prevent the 
action of the atmosphere ; and if a green tint be required, a 
little turmeric mixed with the lacquer will give it. By immers- 
ing the work in a solution of white arsenic in hydrochloric 
acid, a dark-greyish tint is obtained. 

Coating Copper. — To coat with Antimony. — Dissolve 2 oz. 
of butter of antimony in i quart of spirits of wine, and add 
hydrochloric acid until the solution is clear. Into this solution 
put the object to be coated, previously well cleaned and polished. 
In the course of three-quarters of an hour a solid and brilliant 
covering of antimony is deposited. Cast iron fnay be coated 
with copper by placing it in an alkaline solution of chloride of 
copper, and then covered with antimony by the above process. 

Coating Copper. — The best way to coat copper with platinum 
for a battery is to bend a sheet of zinc to enclose a porous cell, 
and connect the zinc without the cell in a suitable vessel with 
the copper in the cell, then fill both vessels with sulphuric acid 
I, water 10, and drop a httle solution of bichloride of platinum 
into the porous cell : it will be instantly thrown down on the 
copper as black powder. 

German Silver, to polish. — An excellent powder for 
cleaning German silver and other bright metals can be made in 
the following manner. Take \ lb. of peroxide of iron (crocus). 
Put it into a wash-basin and pour on water, stirring with the 
hand. While the water is in slow motion, pour off the mixture, 
leaving the grit at the bottom ; repeat this operation, and then 
put it at one side until the crocus has settled at the bottom. 
When it has done so, drain off the water, dry the powder, and 
keep in a bottle or canister. 

If the work to be cleaned is very dirty, mix a little of the 
powder with oil ; rub it on with the fingers, and polish in the 
usual manner. If only slightly tarnished, put a little of the 
powder on a piece of wash leather, and polish well, taking care 
that the leather be free from dust. 

Hardness of Silver. — Goldsmiths often complain of the 
hardness of silver, which is sometimes very difficult to carve, 



ME TALS AND ME TAL- WORKING. 95 

and presents a dead grey cut. These properties are generally 
attributed to the presence of a foreign metal ; but M. Mathey, 
assayer at Locla, has shown that in this silver there is neither 
tin, lead, nor any other injurious metal. He considers this 
property to be due solely to the high temperature at which sil- 
ver is cast. By letting the crucible cool till a slight solid crust 
is formed on the surface of the fused metal, and casting at this 
moment, a soft silver with a brilliant cut is obtained. 

Tarnished Plate, to clean. — Silver or plated objects may 
be cleaned, if tarnished, by dipping them, when they are small, 
into a moderately concentrated solution of cyanide of potassium, 
and when they are large, by brushing the solution over the 
tarnished portions, then washing well with distilled water, and 
afterwards drying with a linen cloth. 

Silver and Galena, to separate. — If sulphuret of silver 
is melted with chloride of lead, a decomposition takes place, 
and sulphuret of lead and chloride of silver is formed. If, 
therefore, galena, which consists of sulphuret of lead with some 
sulphuret of silver, is melted together with chloride of lead, the 
silver is extracted from the galena, and lead takes its place. 
On this principle depends the new process, which is carried 
out as follows : — The galena is mixed with i per cent, chloride 
of lead and 10 per cent, common salt. If it contains much 
silver, a greater quantity of chloride of lead is added. The 
mixture is melted, and the chloride of silver formed by these 
means, together with the salt, floats on the top, and can easily 
be separated from the pure galena. The mixture of chloride 
of silver and common salt is afterwards melted together with 
lime and charcoal, or treated in some other suitable manner, 
whereby the silver and the lead contained in the remaining 
chloride of lead is reduced. The mixture of silver and lead 
thus obtained is afterwards separated in the ordinary manner. 

Artificial Gold. — Take 16 parts virgin platina, 7 parts 
copper, I part zinc. Place the whole in a crucible, covered 
with powdered charcoal, and melt until formed into one mass. 
For a brazing solder, take 1 2 lbs. of copper, and 1 1 lbs. of zinc ; 
flux with powdered brimstone. 

Gold, to Dissolve. — 2 parts hydrochloric acid and i nitric 
acid (aqua regia) will dissolve gold. Apply gentle heat to 



96 METALS AND METAL-WORKING, 

accelerate chemical action. To colour gold, make up 2 dwt. 
of sulphate of copper, 4 dwt. 12 gr. French verdigris, 4 dwt. 
sal ammoniac, 4 dwt. nitrate of potassa, acetic acid about i oz. 
Reduce the sulphate of copper, sal ammoniac, and nitrate of 
potassa to a powder, add the verdigris, then pour in the acid 
little by little ; dip the article in by any convenient means, 
and heat on a piece of copper till black. When cold, place 
in tolerably strong sulphuric acid pickle, rinse well in warm 
water, to which a little potash has been added. 

Case Hardening. — For occasional case hardening upon a 
small scale a very good box may be made by welding a plug 
into the end of a piece of wrought-iron pipe, and using a loose 
plug for the opposite end; the loose plug will, of course, require 
to be fastened into its place with an iron pin passing through it 
and the pipe ; it will require to be luted with clay or loam ; 
part of the plug must project out of the pipe for the convenience 
of pulling it out. 

Composition used in Welding Cast Steel. — Borax, 10; 
sal ammoniac, 2 ; flowers of sulphur, i part ; grind or pound 
them roughly together ; then fuse them in a metal pot over a 
clear fire, taking car« to continue the heat until all scum has 
disappeared from the surface. When the liquid appears clear, 
the composition is ready to be poured out to cool and concrete ; 
being ground to a fine powder, it is ready for use. To use 
this composition, the steel to be welded is raised to a heat 
which may be expressed by *' bright yellow ; " it is then dipped 
into the welding powder, and again placed in the fire until it 
attains the same degree of heat as before ; it is then ready to be 
placed under the hammer. 

Inlaying with Mother - of - Pearl. — Having procured 
mother-of-pearl of the required shades, and properly cut into 
thin scales, fasten the pieces on the article to be inlaid with 
cement, according to whatever design you may have chosen. 
Then cover the rest of the surface with successive coats of 
Japan varnish, baking after each coat, until it is flush with the 
surface of the pearl. 

White Metal is an alloy of 10 of tin, i of copper, and 
I of antimony. This is a capital composition, running 
very smoothly ; when kept from heating it will last longer than 
brass, and with a good deal less friction. It was used a great 



METALS AND METAL-WORKING. 97 

deal for lining the working-parts of eccentrics, also for the stern 
tube bearings of screw propellers, before the introduction of 
the use of timber for this purpose. It is generally cast inside 
of cast-iron steps, merely as a liner, the low temperature at 
which it melts rendering it dangerous to make the whole step of 
this composition, except in cases where the entire bearing is 
enclosed in a bath of oil or water. It is a fact which has been 
practically proved, though not generally known, that for ex- 
tremely high speeds, such as fan-shaft, saw-mills, &c., nothing 
beats cast iron on cast iron. For locomotive-work, or first- 
class engine or machine work of any description, nothing is 
better than what is known by the name of gun metal, which is 
an alloy of i of tin, i of zinc, and 8 of copper. 

Polislied Steel, to Preserve,— You can preserve polished 
steel from rust by mixing some oil with caoutchouc ; melt in 
a close vessel, stirring to prevent burning. A high temperature 
will be required. This will form a perfect air-proof skin over 
the surface, which may very easily be removed by brushing 
with warm oil of turpentine. 

Glazers for Polishing Metal. — There are two kinds of 
glazers for polishing metal, dry and soft. The dry giazer is 
for doing coarse work, and is constructed as follows : — An 
outer coating of wood of a uniform thickness, say 2 inches, is 
secured by means of screws to a cast-iron wheel ; the wood 
must be turned after it is fastened. It is then surrounded by a 
leather strap, which must be thoroughly soaked in water to make 
it pliable. The strap is fastened in this manner : a coating of 
glue is placed on the wood, one end of the strap is nailed to 
the giazer, the strap is then pressed round the circumference by 
means of a round iron bar, and at intervals of 3 or 4 inches a 
row of nails is driven through the strap — these nails are made 
expressly for the purpose, they are round, with square heads 
and polished points, to keep them from rusting and make them 
^easily drawn. The strap having been all nicely secured, the 
giazer is hung up to dry, a process which generally requires a 
week, in consequence of the soaked state of the leather. When 
the giazer is dry enough, the leather is coated with glue, the 
emery is placed on a paper on the floor, a spindle having been 
attached to the giazer. A man is placed at either end of the 
spindle, who rolls the giazer over the emery backwards and 

G 



98 ME TAL S AND ME TAL- WORKING. 

forwards, lifting it up and letting it down, in order to make the 
emery fast, and to cause as much to adhere as possible ; it is 
then hung up to dry, and it is fit for use in a few hours. 

The soft glazer is made all of wood, except that it is secured 
by iron bands. The emery in this case is mixed with tallow 
and formed into cakes. When the emery is to be applied, the 
workman takes a tool something like a hoe with a hammer 
shank, and along the cutting edge is a row of teeth ; he then 
strikes the glazer all round, leaving the teeth-marks as thick 
as possible ; he then takes a piece of cake emery and tallow, 
and presses it all round the glazer ; it is fit for use immediately 
after. No amateur should work on a wood glazer ; because if 
an edge catches the wood, the consequences will be serious. 

Breaking Weight of Cast-iron Rectangular Beams. — 

The breaking weight of rectangular beams may be correctly 
ascertained from data given by Dr Fairbairn. His experi- 
ments on 43 samples of hot and cold blast iron bars, each 

1 in. square, and supported on bearers placed 4 ft. 6 in. apart, 

gave, as the average breaking weight, 45274 lbs. ; hence, for 

any other bar or beam of similar section : — Breaking weight 

4-5^ d2 s 

W = where b = breadth, d = depth, and / = length of 

d 

beam, s — the co-efficient above given — viz., 45274Mbs. If 

the beam be fixed at both ends, it will sustain one-half as much 

again as when supported. 

Preservation of Polished Steel Surfaces. — Polished 
surfaces of steel and iron may be preserved from rusting by 
exposure to water, if whilst so exposed they are covered over 
with a mixture of lime and oil. 

Taking Buckles out of Sheet Iron. — The tools generally 
used are as follows : — A large cast-iron plate, about 2 ft. 
diameter and 2 in. thick, with the face a little convex (it ij 
called a setter), and a hammer of about 4 lbs. or 5 lbs., about 

2 in. flat face. Hammer the sheet iron wherever it is tight, or 
where it does not buckle, so as to stretch it equal to where the 
buckles are ; by so doing you will bring it flat, but this requires 
patience and practice. A large plate of iron, as above stated, 
is the best to set your work out on ; because you can more 



METALS AND ME TAL- WORKING, 99 

easily see the extent of the buckle, and where the tie is located 
that requires to be hammered. The process can be made 
much easier by passing the sheet iron through a pair of rollers 
such as are used by tin and iron plate workers. 

Preservation of Sulphate of Iron. — Mix 4 parts of pure 
crystallised sulphate of iron, and an equal quantity of finely- 
powdered gum arable, with distilled water, and evaporate 
the solution in a water-bath, at a low heat, till it has a suffi- 
cient consistency to be poured out on plates of glass. When 
it has been poured out in this way, and allowed to dry at a 
temperature of 30° Cent, in the dark, it may be cut up into 
lozenges, which can be kept for any length of time in a coloured 
stoppered bottle. 

Composition of Mixed Metals. Pewter. — i. 100 parts 
of tin, 1 7 parts of antimony ; the French add a little copper. 
2. 12 lbs. of tin, I lb. of antimony, 4 oz. of copper. 3. 7 lbs. 
of tin, I lb. of lead, 6 oz. copper, 2 oz. zinc. Melt the copper 
first. 

WMte Metal. — 2 lbs. of antimony, 8 oz. of brass, and 10 
oz. of tin. 

Mosaic Mixture. — Equal parts of tin, bismuth, and mercury, 
forms a metal used for various ornamental purposes. 

Silvery-Looking Metal. — A very fine silvery-looking metal 
is made from 100 parts tin, 8 parts antimony, i part bismuth, 
and 4 parts copper. 

German Titanium. — 2 drachms of copper, i oz. of antimony, 
and 1 2 oz. of tin. 

Spanish Titanium. — 8 oz. of scrap iron or steel, i lb. of 
antimony, and 3 oz. of nitre. The iron or steel must be heated 
to whiteness, and the antimony and nitre added in small portions. 
2 oz. of this compound are sufficient to harden i lb. of tin. 

Columbia Metal. — \\ lbs. of tin, \ lb. of bismuth, \ lb. of 
antimony, and \ lb. of lead ; or, 100 lbs. of tin, 8 lbs. of anti- 
mony, I lb. of bismuth, and 4 lbs. of copper. This alloy is used 
for making teapots, and other vessels which imitate silver. 

Type-Metal of the French letter-founders : 4 of lead and 
\ of regulus of antimony. The letter-founders of Berlin use 
II lbs. of antimony, 25 lbs. of lead, and 5 lbs. of iron. Many 



lOO ME TALS AND ME TAL- WORKING, 

add tin, copper, and brass ; while some make their types from 
3 parts of lead to i of antimony. 

German Silver. — i. 25 parts nickel, 20 parts zinc, and 
60 parts copper. If for casting, add 3 parts of lead. 2. 16 
parts copper, 8 parts zinc, and 3^ parts nickel. 3. 8 parts of 
copper, 3| parts zinc, and 2 parts of nickel. 4. 28 parts 
copper, 13 parts zinc, and y^ parts nickel. 5. Copper, 8 
parts ; zinc, 3 J parts ; nickel, 3 parts. This last is a very 
beautiful compound. It has the appearance of silver a little 
below standard. By some persons it is even preferred to the 
more expensive compound. Manufacturers are strongly 
recommended not to use a metal inferior to this. 

Speculum Metal. — 'i. Copper, 32 parts; tin, 14 parts; 
arsenic, 2 parts. A very good metal. 2. Copper, 32 parts ; 
tin, 1 3|^ parts; arsenic, imparts. 3. Copper, 32 parts; tin, 
15 parts ; arsenic, 2 parts. 4. Copper, 32 parts ; tin, 15 parts ; 
brass, i part ; silver, i part ; arsenic, i part. 5. Copper, 6 
parts ; tin, 2 parts ; arsenic, i part. Sir Isaac Newton's 
mixture. It is very yellow when polished. 6. Copper, 3 
parts ; tin, i\ parts. Compact, and whiter than the last. 
7. Brass, 6 parts ; tin, i part. Com.pact, but too yellow. 8. 
2 parts of 6th composition, and i part of 7th. Much too 
yellow when polished. ^,7, and 8, are experiments by 
Professor Molyneux, F.R.S. 9. Copper, 32 parts ; tin, 2 
parts ; arsenic, i part. A pretty good metal, but polishes too 
yellow. 

Mercury, to Extract. — Make a solution of sulphate of mer- 
cury by dissolving it in a solution of common salt. Add to this 
about one and a half or twice its bulk a solution of protochlo- 
ride of tin (price 3d. per oz.) You will get a white precipitate, 
which will afterwards turn grey. This is metallic mercury. To 
collect it, let the precipitate settle, and pour off the liquid : add 
dilute hydrochloric acid (equal parts of acid and water) to the 
precipitate, and boil. The mercury will gradually collect into 
globules. 

To Prevent Sand sticking to Articles when Moulded.— 
Take a little finely-powdered charcoal, in a fine n^uslin bag, 
and shake it on the face of the flask of sand after moulding 
patterns, and before putting the top flask on, and when well 
dusted with the charcoal, it will prevent them from sticking. 



METALS AND METAL-WORKING. 



lOI 



Shrinking of Castings. — For shrinkage of castings, the 
pattern-maker's rule should be, for cast iron, ith of an inch 
longer per lineal foot ; brass, y^^^ths ditto ; lead, |th ditto ; 
tin, Jg^h ditto ; zinc, y^^-ths ditto. The following is the linear 
expansion by heat from 30° to 212° of — 



Antimony, I 


part in 


Bismuth, 




Brass, 




Copper, 




Flint glass, 




Gold, 




Iron, wrought, ,, 



923 


Iron, cast, I 


part in 


901 


719 


Lead, pure. 




349 


584 


Platinum, 




1131 


581 


Silver, 




. 524 


T248 


Tin, pure, 




403 


682 


Tin, impure, 




500 


846 


Zinc, 




322 




The Amateur's Smelting Furnace. — A simple smelting 
furnace for brass, &c., is made thus : — 

The large vessel No. i is filled with sand, to prevent 
radiation of heat. The 
small crucible stands on 
a grate. i. A large 
tin vessel ; 2. a large 
pot or crucible ; 3. 
a small crucible ; 4. 
coke, or charcoal ; 5. 
a double blast bel- 
lows. 

Tinning. — First cleanse the articles to be tinned by placing 
them in warm water, mixed with a little oil of vitriol. After 
washing the articles in clean water, dip them in a solution of 
sal ammoniac, and let them dry. When they are thoroughly 
dried, place them in a shallow pan, the bottom of which is full 
of holes. When the tin is melted, sprinkle a little sal am- 
moniac over the surface, and dip the pan containing the 
articles into it. When the smoke has cleared away, take them 
out, shake them over the pot, and sprinkle a little sal ammoniac 
over them ; then plunge them into cold water. 

Bisulphide of Tin. — Kletinsky dissolves 4 parts of salt of 
tin in 20 parts of water, previously mixed with 2 parts 
of strong hydrochloric, or i part of strong sulphuric acid. 
This solution is heated nearly to boiling, and then saturated 
with sulphuric acid gas. The following reaction takes place : — 
3Sna + 2HO + SO3, HO + 5502= SnSg + 2(Sn02, 2SO3) + 3H 



lO. 



STEAM ENGINE. 



CI. The yellow sulphide of tin is collected on a filter, washed 
and dried, and the filtrate may be distilled to recover the 
hydrochloric acid, sulphate of tin remaining in the retort. If 
the dried sulphide of tin is sublimed at a red heat, access of 
air being prevented, beautiful mosaic gold is obtained in large 
shining scales, and spangles of a brilliancy that is never seen 
with the old way of making the gold. 

Oxychloride of Zinc may be prepared by dissolving 
granulated zinc in hydrochloric acid, and evaporating when a 
semi-solid hydrated mass is obtained (butter of zinc). The 
oxychloride is prepared by strongly heating this mass in a 
porcelain crucible. 

Working Poor Ores of Lead. — The operation on lead ores, 
which contain too little lead and too much earthy matter to be 
smelted profitably, scientific smelters treat with muriatic acid, 
with heat, upon plates of stone or lead, by which the galena is 
completely converted, if the ore has been properly prepared, 
into chloride of lead. The mass is then lixiviated in tubs with 
double bottoms, holding each 15 or 20 cwt., with boiling water 
to extract the chloride of lead, which crystallises out in great 
part on cooling, the mother liquid being again heated to boil- 
ing, and used over again continually. The deposited chloride 
of lead is reduced to the metallic state by zinc, forming a 
spongy lead, which may be either melted down or used for 

making whitelead, 
&c. Some iron 
having been thrown 
down from the chlo- 
ride of zinc solution 
by chloride of lime, 
the zinc must be 
precipitated by lime 
as pure white oxide 
of zinc, suitable for 
pigmentary pur- 
poses. 

Eotary Engine. 

— The following 
P^^^'^^^^^^^^^^^ sketch and expla- 

nation shows the principle of a simple Rotary Engine : — 




STEAM ENGINE, 



103 



AA, cylinder; B, piston; C, slide; DD, slide box; E, 
exhaust port ; F, steam port ; G, shaft. 

It will be seen that the piston works the slide. 

Steam Governors. — The " pendulum ball '' contrivance is 
probably about the best to employ as a regulator, and about the 
worst to use — as it is ordinarily used — as a governor of machine 
speed. The following invention simply embodies a plan for 
employing the " centrifugal principle '' in the way for which it 
is fitted, instead of (as 
at present in ^' Watt's 
Governor") the mode 
for which it is especially 
unfit. 

The apparatus will 
be easily understood 
from the skeleton dia- 
grams subjoined. 

Fig. I. A is a box 
containing a train of 
clockwork, kept going 
by a spring or w^eight, 
and regulated by the 
conical pendulum B. 
The works are wound 
up every morning when 
the engine starts, and 
thus a rotative move- 
ment is given to the 
wheel C throughout 
the working day, which 
for all practical pur- 
poses may be regarded 
as invariable. 

In fig. 2, A and B 
are two circular discs, 
shown edgewise. One 
face of each, the inner 
one, is flat. On the other, a wheel or pulley is fixed, by which 
rotative motion is communicated. The discs revolve freely and 
independently on fixed axles. One of these discs, A, receives 




Fig, 2. 



I04 



STEAM ENGINE. 



its rotation by a strap from wheel C in fig. i, and therefore 
revolves at a regular rate. Disc B in like manner receives 
rotation from the engine. The discs are so fixed that thin flat 
surfaces revolve in parallel planes, but in opposite directions. 
Through the fixed axles central holes are drilled to receive the 
spindle of the " governor," shown in fig. 3, where A is a spindle 
carrying an arm B, which is crowned by a wheel C, revolving 
freely on its centre. "I'he length of the arm B is rather less 
than the radius of the discs A and B in fig. 2 ; and the diameter 
of the wheel C is just equal to the distance between those 
discs. All these dimensions, as well as the velocity of rotation 
of the discs, are merely matters of convenience. 

When put together, the ends of the spindles pass through 
the holes in the fixed axles, and play freely in them. The arm B 

projects between the 

Fig. 3. 




Fig. 4. 



discs and the wheel 
C, which traverses 
round near their out- 
ward edge, and is 
pretty tightly clipped 
by them. Its rim is 
belted by a ring of 
vulcanite, or other 
elastic material, so 
as to establish a good 
bite. One end of 
the spindle projects 
beyond the frame- 
work, and carries at 
its extremity an end- 
less screw, which 
works into the teeth 
of a quadrant D, 
connected with, and 



governing, the throttle-valve. The wheel arrangement is shown 
in fig. 4. 

The action of the instrument is very simple. So long as the 
"engine'' disc keeps time with the "chronometer" disc, its 
"governor" wheel C will simply revolve on its axis, keeping 
the spindle, and therefore the throttle-valve, fixtures in their 
existing position. When any change of power or load occurs, 



STEAM ENGINE, 105 



and the engine disc begins to gain or lose, the " governor " 
wheel at once begins to traverse round the circle, carrying with 
it the spindle, and thus acting on the throttle-valve until a new 
point is reached, when the disc velocities are again equal ; and 
there it remains until new conditions supervene requiring fresh 
adjustments. 

By this means the engine disc can never vary in velocity 
from the chronometer disc for more than a few seconds at a 
time, while the process of adjustment can be made as prompt 
and delicate as any practical necessities may require. 

Preventing Incrustation in Boilers. — Mr William Irwin's 
invention of "an improved compound for preventing incrus- 
tation in boilers," consists in the mixing with the water in a 
steam boiler a compound composed of the following ingredients, 
which, by preference, are mixed together in the following pro- 
portions : — 

French ochre f lb. 

Oxford ochre J „ 

Brown ochre f „ 

Yellow ochre f „ 

Vandyke brown | „ 

Spanish brown \ „ 

Purple brown \ ,, 

Ground umber f „ 



Ground ochre 4 „ 

6 lbs. 

The above proportions mixed in a gallon of water, and put into 
a boiler 17 by 5 feet, will prevent incrustation. 

Another plan is to introduce a small quantity of chloride of 
ammonium, when the lime which forms the incrustation will 
be held in solution, and the boiler cannot foul. The process 
is equally applicable to fresh or salt water. This will effect a 
saving of time, heat, and fuel, and, more than all, will prevent 
one of the principal causes of explosions, for it has been proved 
that, in most instances, the foulness of the boiler has been the 
principal cause of accident. 

Much of the " fur " in boilers depends on the chemical com- 
position of the water used. Sometimes a pound of common 
soda, introduced daily, has been found to prevent incrustation. 
This for driving a 20 horse-power engine. The deposit is in 



io6 



STEAM ENGINE, 




the state of powder. Two months is too long to work a boiler 
without cleaning, except in rare cases. To introduce the soda, 

have a small cistern 
connected with the 
pump, dissolve in 
the cistern, and then 
turn on your tap. 

Blast Engine.— 

In the following, 
the swan-neck rod 
should be made of 
two flat, tapering 
bars. In the sketch 
the crank is repre- 
sented as working 
6-feet stroke, and 
the cylinder working 
8 -feet stroke. 

Self- Acting Boiler Feeder, — The figure is a section of the 
apparatus. The water from a cistern enters the cylindrical 
reservoir A through the pipe E, closed by a valve B opening 
upwards. The water passes into the boiler through the pipe 

H, closed at top by the valve 
C opening downwards^ and 
closed by a slight spring. 

D is a small steam-pipe 
reaching to the top of the 
reservoir, and having a 3 -way 
cock where shown. The 
action is as follows : — On 
turning the 3 -way cock a 
communication is opened be- 
tween the cylinder and the 
outer air ; the water then 
enters through the valve B, 
and fills the reservoir, ulti- 
mately escaping through the lateral opening in the 3-way cock. 
This shows the reservoir is full. On now turning the cock, the 
lateral passage is closed, and the direct communication opened 
from the boiler through the steam-pipe D. Equilibrium of 




rfrTiTlimrrr 



^3L 



STEAM ENGINE. 



107 



pressure being thus established, the water descends through 
the valve C and pipe H into the bottom of the boiler. On 
again reversing the cock the steam escapes, and the water 
enters as before. 

The only thing to be done, therefore, is to turn the small 
cock at certain intervals, and this may be arranged by letting 
the water that overflows through it when the reservoir is full 
fall into a receiver so arranged as to tilt over when full, and in 
tilting over turn the 3-way cock. The whole would thus be- 
come entirely self-acting. 

Engine Governor. — To make a governor that will work 
correctly and show its speed, mark a diagram of the gover- 
nor, showing the 
centre lines only, 
when in its proper 
working position, 
viz., with the balls 
half expanded. If 
the centre line of 
the long arm be ex- 
panded until it cuts 
the centre line of 
the spindle, we are 
able to measure by 
a scale, on the 

rule, the distance ( j/__\ ' 

from the horizontal 




plane of the balls up 

to the point in the ' \ 

spindle where it is i 

cut by the extended ! 

centre line of the 

arm ; this distance is the vertical height, on the length of 

which depends the speed of the governor. The rule now 

is — 187-5 

V =revs. per min. 

vertical height in inches. 
This gives the correct speed of the governor, and that of the 
engine being also known, before the required size of the wheels 
can be at once determined upon. 



io8 



STEAM ENGINE, 



ric \ 



Expansive Governor for Steam Engines, &c.— It fre- 
quently happens in many manufacturing operations that great 
variations occur in the work which the engine has to perform, 
and in all cases it is desirable that the steam should be used 
in the most economical manner. With the use of the ordinary 
throttle-valve this desirable result is not effected, inasmuch as 
the retardation is caused by expansion of steam before admis- 
sion into the cylinder, thus losing the full benefit of the high 

pressure stored in the boiler at so 
much risk. In order, therefore, to 
economise in this respect to the fullest 
extent, the steam should be admitted 
to the cylinder at full pressure, and the 
required diminution of speed effected 
by a proportionate duration of the 
admission. Such a variable " cut off" 
is produced by the invention we now 
describe. 

Fig. I (the bottom of which is the 
top of the slide-valve case of a hori- 
zontal engine) has cast with it the 
small upright cylinder, closed at top, 
communicating with the valve-case. 
The upper half of this has an opening 
extending about half-way round, which 
is shown as fig. 2. Over this, and 
fitting with proper ease, is another 
cyhnder, open at both ends, and to a 
cross-bar at top is fixed the rod pro- 
ceeding upwards, and working with 
the bent arms of the governor. At 
the lower half is a cavity, as seen in 
fig. 3. Over these is bolted down the 
cylindrical steam-case, provided at the 
side with steam-pipe and at top with stuffing-box, and also with 
support for the bevil-wheel actuating the governor. The revo- 
lutions of this wheel being made, by suitable means, to corre- 
spond with those of the main shaft, and proper adjusting 
weights placed upon the small shelf provided on the rod, going 
through the stuffing-box, the effect will be that, as the centri- 
fugal force depresses the said rod, so will the openings before 




STEAM ENGINE. 109 



described correspond for a shorter time, and the speed be 
regulated as desired. The effect will be better understood by- 
referring to figs. 2 and 3, where, supposing fig. 3 passed across 
fig. 2, in the direction of the arrow, represents the steam on 
during the whole stroke, then by depressing fig. 3, and passing 
it across as before, the inclined sides are brought nearer together, 
and hence the " cut off" takes place sooner. The lower part 
of fig. I is in section. 

The Giffard Injector consists of three cones, A, B, and C. 
B is the combining cone, A the steam cone, and C the receiv- 
ing cone. The steam cone can be moved nearer to or further 
from the combining cone, which is fixed with its small end at 
a short distance from the receiving cone C, and the supply of 
steam can be regulated by the rod D, worked by the hand- 
wheel k, F is the steam-pipe opening into the steam cone 
above ; g is the water-supply pipe opening into cone B. H is 
the overflow-pipe opening into an annular space 00^ surround- 
ing the ends of the cones B and C, finally I is the valve open- 
ing into the boiler. 

The action is as follows : — The steam rushes through pipe 
F and cone A. Now take, for example, the case of a boiler 
working at a pressure of 60 lbs. per square inch from a vacuum. 

A cubic foot of steam at the atmospheric pressure will weigh 
•047 lbs., therefore the weight of a cubic foot of 60-lb. steam 

60 
will be equal to — x '047 — '188 lbs. ; also the weight of a 

cubic foot of water is 62*4 lbs. Now the velocity of issue of a 
fluid under pressure is equal to the velocity of a body falling from 
a height equal to the height to which a column of the fluid would 
be raised by the pressure in question, which for 60-lb. steam 



r^o X 144 



will = 8 V = 8 V44S00 =1712 feet per second. Also for 

188 /60 X 144 



the water velocity will -8 a/ =8 V 1 38-4 = 94 feet per 

62-4 
second nearly. Now, suppose i cubic foot of steam coming 
out of the steam cone with a velocity of 1 7 1 2 feet per second 
to be condensed between A and B, it would form about four 
cubic inches of water, which would retain the velocity of the 



no 



STEAM ENGINE, 



STfAM 




Steam ; and as this is rather more than 1 8 times greater than 
the velocity of the water issuing direct from the boiler, if it is 
mixed with about 1 6 times its bulk of water, it would still have 
a velocity rather greater than 94 feet per second, so it would 
easily open the valve and enter the boiler. 

Now this is exactly what happens in the injector. Steam 
being turned on, rushes through the cones A and B, and 
escapes at the overflow-pipe H ; but by the well-known prin- 
ciples of hydrodynamics, it induces an upward current of water 

in the pipe g : and 
as soon as the water 
reaches the cone A, 
it will begin to con- 
dense the steam, 
and, by the prin- 
ciples already ex- 
plained, if the bulk 
of the condensed 
steam and water be not greater than about 1 7 times the bulk 
of the condensed steam, it will open the valve T and enter the 
boiler. 

If the supply of water be too great, and the velocity thereby 
too much reduced, it will rush out of the overflow-pipe H 
instead of entering the boiler, and thereby give warning to the 
engineman to reduce the supply of water by moving the cone 
A nearer to the cone B, by means of the handle E, until the 
water just ceases to drip from the pipe H. If more water be 
wanted for the boiler, the pointed rod P is drawn further back 
to admit a larger quantity of steam, and the cone A also drawn 
back till a slight drip comes from the pipe H, when the injector 
will be working to its greatest effect. It is evident that the 
quantity of feed-water must in all cases be sufficient to condense 
the steam, and that the water must not be heated to more than 
about 1 10° Fahr., or it will not condense fast enough — or rather, 
the quantity required will be too great for the steam to take 
into the boiler with it. 



Huxley's Internal Tappet Pump or Steam Engine. — As 

a pump this will be found specially useful in deep wells, where 
frequently much inconvenience, loss of time, and expense arises 
from the defective action of the ordinary valves, also necessi- 



STEAM ENGINE. 



Ill 



tating the descent of some one down to the pump. Here we 
have a Hft and force pump, of double action, with the requisite 
changes effected by a tappet piston in place of valves, whose 
action is as certain as the revolution of a crank and fly-wheel, 
the necessary appendage to the piston-rod, &c. Fig. i is the 
ordinary cylinder and piston, the cover, however, having a long 
neck to the stuffing-box in order to allow of the movement of 
the tappet, which is fastened to 
the piston-rod, and may be seen 
just under the stuffing-box. At 
the side, near the top of cylinder, 
are three ports, as usual ; but the 
ports are altered in arrangement, 
as may be seen. The exit port 
b also communicates with the top 
of piston, through a circular pas- 
sage made in the tappet piston 
before referred to, and surround- 
ing the piston-rod. The action 
is as follows : — The piston having 
ascended to the limit allowed by 
the crank, has pushed the tappet 
piston to near the top of cylinder, 
and is ready for descent. Supply 
port a is in communication with 
top of piston, causing it to de- 
scend ; exit port b communicates 
with port c through a cavity, 
which is seen on the side of the 
tappet piston, and thence descends 
a passage and opening c to bottom 
of piston. The piston having next 
arrived at bottom of cylinder, the 
tappet has just pushed against a 
cross-bar provided at the bottom 
of tappet piston, and its position 

is seen in fig. 2, where exit port b communicates through the 
passage described in tappet piston to the top of piston, and 
supply pipe and port a with port c leading to bottom of piston, 
and thus proceeds the up-stroke, and produces the arrangements 
before described ready for another down-stroke. 




1 1 2 STEAM ENGINE, 



Power of Engines. — It is frequently asked, What is the 
power of an engine of such-and-such dimensions ? The ques- 
tion will be answered by a glance at the following rules, which, 
amongst many others, are used for ascertaining the horse- 
power, will explain the vague and uncertain methods we have 
of solving such a problem. In Chambers's " Mechanics," the 
rule for non-condensing engines is. Multiply the area of piston 
in inches by the pressure per square inch in cylinder, less 1 5 
lbs. for the pressure of the atmosphere on waste-steam pipe. 
Then, by the velocity of the piston in feet per minute, divide 
by 33,000, and |- of the quotient is the effective power. 
Templeton's rule for high pressure is, Multiply the area of 
piston in square inches by the average force of steam in lbs., 
and by the velocity of the piston in feet per minute. Divide 
by 33,000, and y^^- of the quotient is the effective power. 
Bourne gives the following rule for high pressure : — Square the 
diameter of the cylinder in inches, multiply by the pressure of 
the steam in the cylinder per square inch, less i\ lb., and by 
the piston's velocity in feet per minute. Divide by 42,017 : 
the quotient is the effective power. The first-mentioned rule 
is merely given by way of illustration, as the pressure of the 
atmosphere is not generally taken into account, engines of this 
principle being supposed to work in a medium. The rules for 
ascertaining the nominal power are equally fallacious. For 
condensing engines Bourne gives the same rule as for non- 
condensing, considering that the deduction of a \\ lb. is rela- 
tively much smaller where the pressure is high, than where it 
does not much exceed the pressure of the atmosphere. Lard- 
ner gives the following rule : — When the pressure in the 
cylinder does not exceed the atmosphere more than 4 lbs. or 
5 lbs., with a good vacuum, and an average of 200 feet per 
minute for the velocity of the piston, square the diameter 
of the piston, and divide by 28 : the quotient is the horse- 
power. The Admiralty rule is. Square the diameter of the 
cylinder in inches, and multiply by the speed of the piston in 
feet per minute. Divide by 6000 : the quotient is the horse- 
power. 

Safety- Valves. — Many and various are the plans that have 
been adopted and suggested for producing perfect safety-valves 
for steam engines. Without an effective and reliable safety- 



STEAM ENGINE, 1 1 3 



valve, the use of a steam boiler must be constantly attended 
with the most imminent danger. Whatever care may be be- 
stowed by the manufacturer on the construction of the safety- 
valve, it may be rendered nugatory by the ignorance or temerity 
of the person in charge of the engine, since he may overload 
the valve, and thus create a pressure within the boiler which it 
was not constructed to endure, and which it may not be capable 
of bearing. The evil may, indeed, be prevented by the use of 
two safety-valves, one of which is beyond the power of the 
engineman. But ingenuity has devised a still more simple 
remedy ; one that not only prevents the production of steam 
at too high a pressure, but which actually causes every attempt 
to produce it to be accompanied by a reduction of pressure, 
and thus removes all temptation to tamper with the valve. The 
new form of safety-valve differs little from the ordinary kind, 
and is extremely simple. In the ordinary kind the fulcrum of 
the lever is absolutely immovable, in the new kind it is fixed ; 
in ordinary circumstances, being kept down by a spiral spring. 
But attempting to overload the valve brings the lever down on 
a stud, which is at the side of the valve most remote from the 
fulcrum, and which comes into action as a new fulcrum by 
supporting the lever, changing the latter from the third to the 
first order. The former fulcrum yields to the additional weight, 
the spiral spring being compressed, and is raised up, the safety- 
valve being at the same time opened, or allowed to open ; and 
thus the steam is permitted to escape, though at a pressure too 
small to raise the valve when weighted as it should be. In its 
normal state, the fulcrum of the lever is at one end, the weight 
at the other, and the power — that is, the tendency of the 
safety-valve to rise — between the fulcrum and weight. When 
the valve is overloaded, the weight — that is, the resistance of 
the spiral spring — is at one end, the power — that is, the weight 
with which the lever is loaded — is at the other, and the ful- 
crum — that is, the stud on which the lever has been brought 
down by the overloading — is between the power and weight, 
the effect of the latter being aided by the tendency of the steam 
to raise the valve. A notice of some of the most recent, there- 
fore, cannot but be interesting to mechanicians and engineers. 
First, we have 

Mr SwamUs Patent, — In this case, the apparatus is so 
arranged that undue weight appHed to the lever of the valve, in 

H 



114 



STEAM ENGINE, 



place of allowing an increase of pressure in the boiler, will 
cause the steam to blow off at any pressure to which the appa- 
ratus may be set. In place of arranging the valve lever to 
turn on a fixed centre as usual, the centre or axis is arranged 
in such a manner that it is kept down only by a spring or 

weight, which yields 
when undue pres- 
sure is applied at 
the other end of the 
lever ; the outer 
arm of the lever 
then descends a 
short distance till 
it comes against a 
fulcrum arranged 
for it between the 
valve and the 
weight, and then 
the undue weight 
applied to the lever 
aids in taking pres- 
sure from the valve. 
The inner end of 
the lever, with its 
centre or axis, is 
cased in so that it 
cannot be tampered 
with. The same 
arrangement is ap- 
plicable where an 
adjustable spring is 
applied to the outer end of the valve rod in place of a sliding 
weight. 

Fig. I is a side view, fig. 2 a plan, and fig. 3 is a vertical 
section of a safety-valve constructed according to this inven- 
tion. 

a a\s z. casting secured by bolts to the top of the steam 
chest ; ^ is a bushing of brass fitted into it to form the valve 
seat ; c is the valve, held down by the weight lever dy which 
turns at one end of the pin, e^ and at the other receives the 
sliding weight/, and by shding this weight on the lever d, the 




STEAM ENGINE. 



115 



pressure on the valve may be varied as desired, g is the ful- 
crum to which the lever d is jointed by the pin e^ and this 
fulcrum is made so as to yield when a heavy pressure is put 
upon it. Its stem, g^^ drops into a socket bored to fit it in the 
casting a^ and in a space within this casting the stem, g^^ 
receives the spiral 
spring h^ which is 
retained by the nut i 
on the stem, so that, 
as will be seen, by 
screwing up the nut 
/, the fulcrum g may 
be held down in its 
socket with any de- 
sired force. A con- 
venient way of ad- 
justing the spring h 
is to place a suitable 
weight,/, at the end 
of the lever, and to 
screw up the spring 
/ until its tension is 
just sufficient to hold 
down the fulcrum g; 
k is a stud or stop 
fixed in the casting 
^, in such a position 
that, as soon as the 
fulcrum^commences 

to yield in consequence of an excessive weight being applied to 
the lever d^ the said lever may come down on to the stud, 
which then acts as a new fulcrum, and the excessive weight 
applied then assists the pressure of the steam in lifting the 
valve ; / is a cover with openings in it for the passage of the 
lever d^ and for the escape of the steam ; it is secured by 
screws or otherwise to the casting a^ so that the valve may 
not be tampered with ; 7n is a screw plug, which closes 
the recess in the casting a^ in which the spiral spring is con- 
tained. 

In connection with safety-valves arranged according to this 
invention, apparatus may be applied to indicate when the 




ii6 



STEAM ENGINE. 



water in the boiler is deficient by causing the steam to escape 
from the valve. Fig. 4 shows, partly in section, apparatus for 
this purpose ; ;/ is a bushing screwed into the top of the boiler, 

and <9 is a plug passing 
freely through it; a 
valve, ^', is formed at 
its lower end, and this, 
resting against a face at 
the lower end of the 
bushing, prevents any 
escape of steam ; p is 
a spiral spring, which 
tends constantly to draw 
the valve 0^ up to its 
seat ; $r is a chain con- 
necting the upper end 
of the plug o with the 
outer end of the weight 
lever d of the valve ; r 
represents a heavy float 
connected by .a chain 
with the lower end of 
the plug ^, and which 
should rest on the sur- 
face of the water in the 
boiler ; when, however, 
the water falls too low, 
this float, being unsup- 
ported, its weight draws 
down the plug ^, and 
by the chain q the 
weight of the float is 
transmitted to the lever 
</, and this additional 
weight causes the pressure on the safety-valve to be reUeved, 
as already explained. 

What is claimed is the arranging the parts of a safety-valve, 
as hereinbefore described, and especially the combined applica- 
tion to safety-valves of a yielding fulcrum for the valve lever, 
and a stud or stop to receive and support the valve-lever as 
soon as the fulcrum commences to yield. 




STEAM ENGINE, 



117 



Peefs Invention, — The accompanying illustration represents 
a valve patented by Mr S. J. Peet, of Nev^r York, which is well 
spoken of on account of the simplicity of its construction and 
the ease with which it may be repaired. 

From the engraving representing the valve in section, it will 
be seen that the two discs serving to close the valve are raised 
or depressed by means of the hand-wheel and upright stem B. 
These discs are suspended on the stem by its collar engaging 
with the semicircular recesses on their inner faces, and pre- 
vented from separat- 
ing from the stem 
by the walls of the 
passage in which 
they move. The 
lower face of the col- 
lar, B, and the lower 
portion of the reces- 
ses in the discs are 
made slightly coni- 
cal, so that, after the 
discs have reached 
the bottom, any 
further pressure on 
them by the screw 
of the stem forces 
them apart and firmly 
against the walls of 
the valve, thoroughly 
closing the apertures 
of the pipe. The 
conical collar, there- 
fore, acts as a wedge aided by the pressure of the screw. It 
will be seen that both sides of the pipe are closed by this means, 
making this a back-pressure valve as well as a direct acting 
gate. When the discs are raised, a free passage, without 
change of direction, is made through the valve for the steam, 
water, or gas, of the full size of the pipe. The stem is packed 
in the usual manner by the screw gland D. 

Safety- Valve Balance. — This is the safety-valve and balance 
used on the principal railways. The lever D, fig. i, is affixed 




ii8 



STEAM ENGINE, 



to a spring- balance A, graduated to the pressures per square 
inch due to the spring. By turning a nut B on the stem of the 
spring-balance, any required pressure can be thrown upon the 
valve, which is kept down by the spring acting on its lever. 
Should the pressure within the boiler exceed that to which the 
balance is adjusted, the valve is opened, and a portion of the 
steam escapes. The lock-up safety-valve, fig. 2, consists of a 

valve pressed down 
v\ C.I ©B by a set of strong 

springs C,the whole 
enclosed within a 
box under lock 
and key. While 
the engine - driver 
has command over 
the sprir^-balance 
valve, so as to in- 
crease or diminish 
the load at plea- 
sure, the lock - up 
valve is inacces- 
sible to him, and 
opens whenever he has loaded the open valve beyond the 
pressure to which the lock-up valve has been adjusted ; thus 
serving as a check upon him in case of his working at a dan- 
gerous pressure. 

Safety- Valve and Superheater. — The following is the 
arrangement of the safety-valve in general use in marine 
engines : — A is a handle with socket attached, the outside of 
which socket fits into the top of dome or upper part of valve- 
chest B, and internally fitting the valve-spindle E. D, D, &c., 
are the lead weights entirely enclosed in^the valve-chest B, C, 
which is generally cut in two for the purpose of removing the 
weights on examining the valve and seat F, G. Now for its 
action through the sockets of A and the upper end of spindle E, a 
cotter is fitted loosely and bored in the point to receive a pad- 
lock, the key of which is given in charge to the captain of the 
vessel. It will be seen that the cotter hole in spindle is much 
longer than that of the socket A, which allows the valve and 
weights when counterbalanced by the pressure in the boiler to 




STEAM ENGINE, 



119 



rise sufficient to allow 
being eased by hand 
in the engine - room, 
which can be effected 
as shown by the dotted 
lines. As the cotter 
rests on the top of 
the projection of B, it 
allows the valve to be 
moved freely on its 
seat at any time, and 
at the same time pre- 
venting any weight 
that may be placed on 
A from taking effect 
on the valve. The 
superheater is used for 
the purpose of drying 
the steam immediately 
after its generation in 
the boiler, and to pre- 
vent as much as pos- 
sible the condensation 
of the same while on 
its passage from the 
boiler to the cyhnder. 



a free escape of steam, independent of 

A 




New Slide- Valve. — This equilibrium slide-valve is intended 

FIC. I. 




to prevent the waste of steam in the ports of cylinders. C is 



I20 



STEAM ENGINE. 



the face on the back of valve BB, the movable face and ex- 
haust-pipe E is the set screw to screw down the packing 



ric.2. 




SECTION 



gland with crossbar A. Another modification of the valve is 
shown at No. 2 ; the ports in this valve are placed to one side 

of the valve face, and the exhaust-pipe 
BB is cast to the back of the valve, 
which oscillates on the centre stud D 
and exhaust-pipe BB, covering alter- 
nately the top and bottom ports. 

Safety- Valve. — This safety-valve is 
designed for a small cylindrical (model) 
boiler, 12 in. in diameter by 24 in. in 
length. 

The valve, with its seat and dome, 
are of brass. The ball] may either 
be solid or hollow. Being a true 
sphere, it is perfectly free to move in 
its seat, without the possibility of stick- 
ing, whenever the pressure of steam in 
the boiler is beyond that for which the 
lever is weighted. The dome serves to 
protect and guide it in its seat. 

A serious objection to many of the 
valves now in use, particularly those of 
the " mushroom '' form with stem and 
guide, is their liability to stick, and 
disastrous results have often happened 
from this defect. Perfect freedom of action and non-liabihty 




STEAM ENGINE, 



121 



to Stick, are therefore important features in the construction of 
a safety-valve. The principle of the ball valve is not new. 

CLEVATICIN 




A New Safety- Valve. — The following is a design for a 
safety-valve which will register the pressure of steam as well as 




allow it to escape : — The valve, it will be perceived, ascends as 
the pressure increases^ and descends as the pressure decreases. 



122 



STEAM ENGINE. 



BB are two bars fixed for the valve-rod to slide through to 
guide. At the top of the valve-rod R, there will be perceived 
a small roller to make it run free under the lever L. 

Slide- Valve Motion. — Many possessors of small cylinders 
— say ij-in. bore and 3 -in. stroke, with steam chest on top — 
are puzzled to know how to communicate motion to the slide- 



ELtVATIOlM 




END ELEVATION 




valve, so as to be out of the way of the crank and the connect- 
ing-rod. The following plans will suffice : — ^, the cyhnder, ^, 
brackets screwed on back of cylinder flange carrying shaft c^ 
on which is fixed two arms d^ d^ one connected with the eccen- 
tric and the other to give motion to the valve. The arm d' 
has a slot for changing the length of stroke ; the connecting-rod 



STEAM ENGINE, 



123 



is screwed into the eccentric strap for setting valve with the nut 
e for tightening when set, /is the support for valve-rod. 




Another method is shown in this diagram, which sufficiently 
explains itself. 



124 



STEAM ENGINE, 



Another plan: A, Crankshaft; B, fly; C, eccentric ; D, horizon- 
tal lever with eccentric-rod on one end, valve-rod on the other. 




/ 



The following plan is generally adapted to cylinders with 
valve on top : — It is a spindle on brackets, with lever near the 




middle, connected with the valve-spindle by two links. A nut, 



STEAM ENGINE, 



125 



with a pin formed on each side, is taped and screwed on the 
valve-spindle, in order that the valve may be set to a nicety to 
the end of the spindle, fig. 3. Another lever is fixed, with a 
long hole at the end, and a pin is inserted on which hangs the 




eccentric-rod. By having a long hole and movable pin, the 
stroke of the valve may be set to the desired length. Fig, i is a 
plan; fig. 2, elevation; fig. 3 shows the rocking-shaft or spindle 
laid with the levers and links attached to the valve spindle. 

Another method is shown in next diagram : — A is sole plate, 
B cylinder, C connecting-rod, D rocking-shaft, E levers on 




rocking-shaft, F pedestals to carry rocking-shaft, G eccentric- 
rod, H connecting-rod for slide-valve. 

Reversing Motion in Engines. — The following is a simple 
arrangement for altering an engine, so that you may reverse it 
at will, which can be done according to this plan with one 



126 



STEAM ENGINE. 



eccentric, and doing away with eccentric-rod, and using a longer 
valve-rod and a link :— Fix a plate to the eccentric-strap, and 
also a link (as will be seen in sketch) extending from D to D\ 




B is a rock-shaft working on a pin iixed to centre of plate it 
and another pin fixed at F on a plate bolted to engine-stand. 
When the engine is at work the rock-shaft will give motion to 
link as if using two eccentrics ; and by moving the lever G to 
the dotted hnes G', the sliding-block will be moved from its 
position at top of link (as seen in sketch) to the bottom of link, 
and so alter position of slide-valve and reverse the engine ; and 
by moving the lever G into some of the notches marked at H, 
the travel of valve will be short, and so allow the steam in 
cylinder to expand by closing the ports sooner, and allowing 
less steam to enter the cylinder. The parts G, H, J, K, and L 
can be fixed to engine-frame or stand in any position best 
suited to the plan of engine. 

Setting the Slide- Valve.— First, the steam is to be shut 



STEAM ENGINE. 



127 



off a little before the end of the stroke by closing the aperture 
of the steam-port which causes the piston to be brought gradu- 
ally to rest without jarring the engine. Secondly, the eduction- 
port or passage to condenser should be closed before the end 
of stroke, which is called " cushioning " the piston, because it 
then completes the stroke against an elastic air-cushion in con- 
sequence of' a portion of uncondensed vapour being shut up 
between the piston and the top or bottom of cylinder. Thirdly, 
the steam-port on the same side of the piston should be opened 
a very little before the end of the stroke, so that the steam may 
have acquired its full pressure as soon as the crank shall have 
turned the centre ; and lastly, the communication with con- 
denser should also be opened on the opposite side of the piston 
a little before the end of stroke, so as to have a vacuum ready 
made in the cyhnder before the return stroke begins. 

Boiler Feeding. — Several modes of feeding a boiler without 
a pump have been suggested from time to time, but the follow- 
ing will be found 
practicable : — A 
is the steam-boil- 
er, and B a tank 
some distance 
above ; is fed by 
a pipe F, with a 
flap-valve opening 
into the tank as 
shown. This tank 
is also connected 
with the boiler by 
two pipes C D, in 

each of which is a cock C D^ connected by levers with slotted 
eyes to a pin, on the end of a rod of iron H ; the other end of 
the rod is coupled to the .float E inside the boiler. 

The action is as follows : — Suppose the water in the boiler 
was to get low, then the float E would go down with it, bring 
down the slotted levers and open the cocks C^ D^ in the pipes 
C D, which would open two communications between the boiler 
A and the tank B ; the pipe C letting steam into the tank and 
forcing the water down the pipe D till the water in the boiler 
regains its level when the float rises, shuts the two cocks, and 




128 



STEAM ENGINE. 



cuts off the communication with the tank, which then fills again 
through the pipe F. The flap-valve is to prevent the water 
returning down the pipe F. 

Boiler Constnicfion. — The fire tubes passing through the 
steam space of boiler would not heat the steam, but would con- 
dense it, in proof of which 
an egg-shaped boiler in 
work had the flues built 
2 inches higher than the 
water-line, and was in 
consequence unable to 
keep up a constant sup- 
ply of steam. But when 
the flues were lowered 
2 inches below the water- 
line, a sufficient supply 
was kept up. The up- 
per tube plate, though 
placed in a horizontal position, would not impede the rising of 
the steam. The dotted line in sketch shows where the flues 
were lowered to. 




Boiler Working. 




An old rule for Cornish, and 2-flued 
boilers, is to allow 5 
square feet of water 
surface per horse- 
power of boiler ; there- 
fore we make the total 
boiler horse-power 
from \\ times to 2 
times the nominal 
horse-power of engin e 



E J 




Kemp suggested the following : — A. 



Steam -Propeller 
for Model Boats. — 

Various contrivances 
have been adopted 
from time to time 
for propelling small 
boats. Mr W. G. 
boiler; B, furnace; C, 



STEAM ENGINE, 



129 




steam-pipes ; D, safety-valve ; E, guage tap. The steam-pipes 
should be made of indiarubber. 

This, on examination and trial, proved to be a failure, as the 
steam condensed with propelling the boat ; but it was found 
that, if the end of the steam-pipe were brought to a point with 
a very small hole in it, and inserted into another pipe, so 
shaped as to leave a space all round the entrance of the point of 
the steam-pipe, the rush of the steam drew in with it a quantity 
of air, which it forced out of the stern of the boat, and conse- 
quently forced it through the water at a very fair speed. It 
answered better when the keel of the boat was made wide at 
the stern, and two thin pieces of metal were fastened on the 
side, so as to force 
the air direct astern, 
than when the pipe 
alone was brought 
through. 

A, pieces of thin 
metal fastened each 
side of keel ; B, 
point of steam-pipe 
entered into the air-pipe; C, steam tap ; D, D, water-level taps ; 
E, spring safety-valve ; G, pipe attached to valve to carry off 
waste steam ; F, water level ; H, spirit lamp. 

Another method is described in the following diagram : — A, 
a hollow ball ; B, 
steam - pipe from 
boiler to ball ; C, 
pipe from ball 
through bottom of 
boat ; and D, pipe 
from ball through 
stern of boat. To 
the end of steam- 
pipe B is attached 
a nozzle, which pro- 
jects within theball 
fullypast its centre, 
about in a line with 
the far side of pipe C, as shown by dotted lines at E. The 
force of the steam in rushing through the nozzle tends to form 

I 




I30 RAILIVA YS AND LOCOMOTIVES. 

a vacuum within the ball ; immediately the water rushes up the 
pipe C, and, being caught by the steam, is forced through the 
pipe, and so keeps up a continuous stream. 

The general principle of the screw-propeller may be thus 
described : — If a thread be wound upon a cylinder equal dis- 
tances apart, it will trace a single-threaded screw ; if another 
thread be wound on the same cylinder between the first thread, 
they will trace a double-threaded screw. Now, if the threads 
be supposed to be raised into a very deep and thin spiral 
feather, and the cylinder be supposed to become very small, 
then a screw of the proper kind will be obtained for propelling 
vessels, except that only a small piece of such screw must be 
employed. A two-bladed propeller is a short piece of a double- 
threaded screw, a three-bladed propeller is a short piece of a 
triple-threaded screw. The diameter of the screw is the circle 
described by the extremities of the arms, the pitch is the dis- 
tance in the line of the shaft from one convolution to the next. 
Sometimes screws are made with an increasing pitch in the 
direction of their length, also from centre to circumference. 
The original screw propellers were made with several convolu- 
tions, but are now reduced to about i-6th of a convolution. 
The term length indicates what portion of a convolution is 
employed. If a screw of 9 ft. pitch has i-6th of a convolution, 
the length will be i ft. 6 in. The slip of the screw is the differ- 
ence between the actual speed of the vessel and the speed it 
should attain if the screw worked in a solid nut ; this is called 
the positive slip. There is also the negative slip, where the 
velocity of the vessel is actually greater than if the screw 
worked in a solid nut, though the latter is not of very frequent 
occurrence. 

Railway Signals. — All travellers by railway are familiar 
with the ordinary mode of signalling by means of movable 
arms or semaphores and lights, and probably not a few of them 
are acquainted with the signalman's jingle — 

** White for right, red for wrong, 
And green for gently go along ! " 

But the best system is that now adopted, first, we believe, on the 
South-Western system. 

After the introduction of Mr Preece^s plan of Block SignaHing 
on the South-Western, these repeaters, which are similar in 



RAILWAYS AND LOCOMOTIVES. 



131 



FIG. I. 



FRONT 



VIEW, 



construction to the block instruments, were fixed in one or two 
places for experiment, and the experiment was so successful, and 
their use so valuable, that they were gradually extended. 

The great merit in these 
signal instruments is the assi- 
milation of the indoor or block- 
signal to the outdoor, so that 
if a semaphore, disc, or other 
signal be used on the line to 
warn the engine-driver, the 
man who has that signal under 
his control is himself in the 
first place warned by a similar, 
but miniature, semaphore or 
disc inside his box, so that 
where it is necessary that a 
signal should be repeated and 
made visible to the signalman, 
the signal in his box is made 
similar in form, but in minia- 
ture, to the outdoor signal 
itself. Every motion, there- 
fore, of the signal- lever would 
produce a corresponding result 
upon the small signal, enabling 
the signalman to see instantly 
whether all was right. 

In fig. I will be seen a front 
view of a small semaphore ; 
fig. 2 shows an elevation of 
the interior arrangements, both 
of them showing the sema- 
phore arm down, giving the 
" All clear " signal. A is a 
strong horse-shoe electro-mag- 
net fixed at the bottom of the 
box. B is the armature pivot- 
ed at G, and weighted at W 
by a small weight, which is made to slide up or down the 
armature lever between G and C. At the end of this lever, at 
C, is attached a long lever to the head of the semaphore arm. 




RAILWAYS AND LOCOMOTIVES. 



The armature has a limit to its movements by the stops at F 
and E. 

It will be seen that any motion up or down of the armature 
must exercise an opposite motion of the long lever CD, and 
exercise an influence upon the arm to raise or depress it. A 
current of electricity passing through the electro-magnet would 

at once exercise mag- 
netic effect, and cause 
the armature to be 
attracted ; this would 
have for effect the 
immediate raising of 
the semaphore arm, 
which would remain 
in that position so 
long as a current 
flowed round the 
magnet; immediately 
on the cessation of 
the current, the elec- 
tro - magnet would 
cease its action, the 
armature would, by 
reason of the weight 
W, be restored to its 
original position, and 
the arm would fall 
and give the ** All 
clear" signal, as in 
the diagram. It will 
be seen, therefore, 
that by the action 
and cessation of a 
current we can raise 
or depress a sema- 
phore arm ; and that 
if there be contrived 
connection with the outdoor 




some automatic arrangement m 
signal to effect this object, we have at once a faithful repeater 
in the signalman's box of the outdoor signal, however distant it 
may be. 



RAILWA YS AND LOCOMOTIVES. 133 

Such an arrangement as the following has been adopted. At 
the head of the semaphore, close to where the arm is pivoted, 
are fixed, one on each side, and insulated from each other, two 
springs, the one in connection witlt a live wire to the signal- 
man's box, where it is attached to one end of the electro- 
magnetj the other spring is in direct communication with the 
earth. Upon the arm itself is fixed a piece of brass, so that 
when the arm is raised it presses up between the two springs 
and completes the circuit, but only when the arm is almost 
fully raised. In the signalman's hut is placed a battery, one 
pole of which is to earth, the other to the electro-magnet. The 
battery circuit is, therefore, through the electro-magnet, insula- 
tion taking place at the spring of the semaphore. In this 
position, therefore, the miniature semaphore is at " All clear '* 
the same as the distant signal itself. Immediately the signal- 
man moves his lever to alter the signal, the arm is raised, the 
brass piece on the arm completes the electric connection 
between the insulated spring and the earth spring, the battery 
is at once brought into play, the magnet acts, the armature is 
attracted, and the small semaphore arm is raised to '' Danger," 
corresponding with the outdoor signal. The whole of this 
takes place in a far shorter time than it has taken us to 
describe. The action is almost immediate ; so long, therefore, 
as the arm is raised to the position of *' Danger," the miniature 
arm faithfully reflects that position ; but as soon as the lever 
is restored to its original position, the distant signal is lowered, 
the circuit is broken, and the armature is at once released, the 
small arm therefore falls, and shows the state of the distant 
signal. Should the miniature arm remain down when the 
signalman puts his lever over, he is at once aware that his wire 
or part of the signal apparatus is out of order, and would con- 
sequently take immediate steps to put it right. 

In order that the battery may not be wasted, it is arranged 
that the signal which is used less than the other should attract 
the armature : thus at a junction the " Danger" signal is con- 
stantly in use, the '' All clear " only to admit a train. At a 
station the distant signal is generally at " All clear." So in 
the one case we want the armature when attracted to lower the 
arm, and in the other to raise it. By referring to the sketch, 
the attraction of the armature will in this case raise the arm ; 
but if the lever on the arm be fixed in front instead of behind 



134 



RAILWAYS AND LOCOMOTIVES. 



the pivot D, the attraction will raise it, and 7nce versa. When 
it is necessary that the ** All clear" signal or the lowering of 
the arm should bring the battery into play, then the insulated 
springs must be placed at the back of the semaphore, and the 
brass connecting-piece at the back of the arm. When so 
placed, no current is passing when the arm is raised ; the re- 
peater, by gravity, has its arm up ; but when the signal-arm is 
lowered, it makes connection, the electro-magnet is brought into 
play, and the small arm is lowered. 

As semaphores are now being generally adopted everywhere, 
we have described the arrangement adopted, but on various 

lines there are differ- 
ent signals in action 
to which these re- 
peaters are equally 
applicable. On the 
South - Western the 
disc, on the Great 
Western and North- 
western the disc and 
bar, as the following 
sketches, 3 and 4, 
show. Instead of an 
up-and-down motion, 
these signals are al- 
tered by a circular 
movement. In fig. 
4 is a miniature 
" disc," the interior 
arrangement of the 
electro - magnet is 
similar, but at the end of the armature is placed a rack which 
works into a pinion fixed on the rod that carries the disc. The 
attraction and release of the armature conveys a circular motion 
to the rod ; the disc is consequently moved from the one posi- 
tion denoting "Danger" to the other denoting *^ All clear." 
As the motion of the disc outdoor is different to that of the 
semaphore, the connection necessary to put the live wire to 
earth is consequently different. 

Upon the wooden upright that carries the disc-rod is placed 
a piece of brass, fitted with a spring to ensure contact ; this is 




RAILWAYS AND LOCOMOTIVES. 



135 



properly connected, and is protected from wet by an iron roof. 
Upon the rod which is in connection with the earth is fixed a 
second piece of brass with a spring ; this is fixed at the same 
height, and is so connected that when the disc is turned these 
springs make a good rubbing contact. 

The action is of course similar to that of the semaphore : 
hnmediately the lever is pulled, the disc turns round and the 
springs make connection, the armature of the miniature disc is 
attracted, and by the rack-and- 
pinion movement the disc is 
turned into a position corres- 
ponding with the outdoor signal. 
When the disc is turned the 
opposite way, or to " All clear," 
contact is broken, the weighted 
armature falls back, and " All 
clear '^ is shown in the signal- 
man's hut. The contact arrange- 
ment on the outdoor signal is 
similar to what would be applied 
to signals such as are used on 
the Great Western. To make 



FIG 4 



the miniature signal agree, it is 
only necessary to fix, instead of 
the disc, a disc and bar, as in 

fig. 3. 

Many of the discs and Sema- 
phore repeaters have been fixed 
on the South-Western and other 
lines for some years ; they give 
great satisfaction, and continue 
to work well. In places where, 
during fine weather, the signal is 

visible, yet in consequence of the place being situated low, and 
being liable to fog, there are very many days in the year when 
the signal is invisible. In such places some extra precaution 
of this nature should be taken. 




Electric Railway Signal. — The object of this new appa- 
ratus is to prevent the possibility of a signalman signalling that 
the line is clear until the train which should control his move- 



136 



RAILWAYS AND LOCOMOTIVES. 



ments has actually passed his box. There is applied to the 
switch or lever of the railway- signal telegraph apparatus a means 
of locking the handle or lever after it has been used to adjust 
a signal, and of retaining it in a fixed position until released by 
the action of a passing train, which will remove the cause for 
retaining, say, the danger-signal in a fixed position. 

Fig. I is a back view of the apparatus, fig. 2 an inverted 
plan view, and fig. 3 a vertical section taken in the line 1,2, 




of fig. 2. 7'he switch- lever apparatus is connected (as shown 
at A, fig. 4) with the railway by an arrangement of levers and 
rods, which are set in action by the passing train for the pur- 
pose of withdrawing a restraining bolt applied to the handle or 
lever of the switch apparatus, and thereby leaving it free to be 
set in action by the signalman. 



RAIL WA YS AND LOCO MO TIVES. 137 

a is the handle or lever of the switch apparatus mounted on 
a centre at b^ the bearing for which is insulated by being let 
into a table of wood c. Fitted to opposite sides of the switch 
handle are the spring-clips a" d"^ which are intended to embrace 
the divided bridge or insulated segment-plates d d^, connected 
by clamping nuts e e^^ to electric wires leading to the terminus 
e^ e^. The switch-lever is also in metallic contact with a wire 
leading to the terminal e^, A pin d at the lower end of the 
switch-lever a projects into the forked end of a bell-crank 
lever f, mounted on the under side of the table, and fitted at 
its opposite end with a spring catch or tumber f^. As this 
switch-lever a is moved it will give a rocking motion to the 
bell-crank lever, for the purpose to be presently explained. The 
lower part of the switch-lever has a notch cut in its edge to 
receive a sliding bolt g, by which it is locked in its normal 
position. This bolt is carried by a slotted guide-bar g^ through 
the slots of which screws are passed for securing it to brackets 
attached to the under side of the table. This guide-bar is pro- 
vided on its face with a pin g^, against which the spring-catch 
f is intended to strike in one direction of its motion, for the 
purpose of driving that bar forward, but on its return motion 
the spring-catch slides over the pin. Upon the edge of the 
guide-bar is a second pin or projection g^, through which the 
bar receives an endway motion in the opposite direction to that 
imparted by the bell-crank. This pin g^ is acted upon by a 
pendant-lever h, which is itself acted upon by a vertical rock- 
lever /, fig. 4, connected at its lower end to a sliding-rod h ; 
this rod k is caused to bear against a horizontal-lever or switch 
/, applied to the railway track, as shown at fig. 4 ; and in plan 
view at fig. 5, a spring m^ or a weight, being used to keep the 
rod up to its bearing. Supposing now a train to be passing 
along a line fitted with the locking apparatus above described 
in the direction of the arrow, fig. 5, the switch or lever /will, 
by the lateral pressure it will receive from the flange-wheels 
passing between it and the fixed rail, be rocked, and it will thus 
give an endway motion to the rod or tracker k^ which will in 
its turn rock the levers / and h^ and the latter, striking against 
the pin on the bar ^% will drive it and the bolt which it carries 
into the dotted position of fig. 2. The switch-lever will, there- 
fore, be free to be moved from the drawn to the dotted position 
of fig. 3, for the purpose of operating a distant signal. 



138 RAILIVA YS AND LOCOMOTIVES. 

As this apparatus is specially adapted for use with Mr 
Preece's block-signal telegraph apparatus, in which the sema- 
phore arm is maintained by a weight and depressed by the 
action of the electric current, it is used in the following manner, 
viz. : — The terminal e^ is connected with the earth, the terminal 
e^ with the battery, and the terminal e*' with the line wire. 
When, therefore, the hand-lever is in the drawn position of fig. 
3, which is its normal position, there is no current passing 
through the distant signal apparatus which the switch apparatus 
is intended to control, and the block-signal is consequently up; 
on the other hand, when the hand-lever is in the dotted posi- 
tion, the current will pass through the distant signal apparatus, 
and retain the semaphore arm at the depressed position, thereby 
indicating ** line open." If now the signalman at the distant 
station A signals to the man at station B, that a train has 
started from A in the direction of station B, the duty of the 
receiver of this signal will be immediately to raise the block- 
signal at station A ; this he will do by throwing over the 
switch-lever B into the drawn position ; but in the act of doing 
this he will cause the bell-crank lever / to strike the pin g^ on 
the sliding-bar g-^, and throw the bolt g into the notch of the 
switch-lever ; the lever will therefore remain fixed, and be 
beyond tlie control of the signalman at station B. As soon, 
however, as the advancing train passes the switch or lever /, 
and sets the rod k and lever / h in motion, as above explained, 
the guide-bar g^ and bolt g will be returned to the dotted posi- 
tion of fig. 2, and the signalman will then be able to set his 
switch apparatus in action. If, however, he should delay in 
communicating the proper signal to station A that the line is 
open, no casualty can arise, the only inconvenience being the 
undue blocking of the line. 

This apparatus is in practical operation on the London and 
South-Western Railway, and is spoken of very highly. 

Fog Signals. — The following plan, if capable of being 
reduced to practice, would displace the explosive fog signals 
now in use. It also acts as a distant signal. The original 
part of the proposal is the adaptation of the bell-crank lever H, 
so as to strike a bell F in a passing train by means of a lever 
G, or similar contrivance placed outside the guard's van and 
engine. It will be seen by looking at the dotted lines that 



RAIL WA YS AND LOCO MO TIVES. 



139 



when the semaphore L is down, the lever B is lowered, and 
causes H to fall belcJw the level of the lever G, attached to the 
train. Therefore, only when the semaphore is at danger is the 
bell struck to warn 



the guard and 
driver. The lever 
H is put so far 
down the line as to 
enable the driver 
to stop the train 
on arriving at the 
semaphore post. 

A, signal-post ; 
B, lever, with 
weight ; C, wheel 
at the signal-box or 
station; D, railway 
line ; E, hammer ; 
F, bell ; G, lever, 
with weight ; H, 
bell-crank lever ; I, 
chain to connect H with 
L, semaphore. 




B ; K, chain to connect C with B 




FiC.2 



PLAN 



^ 



Self- Acting Railway Signals. — i. Below is a self-acting 
signal, said to possess advantages over previously-invented 
plans of self-acting 
signalling. Fig. i 
is an elevation ; 
fig. 2 a plan. The 
same figures refer 
to both drawings. 
On the train pass- 
ing the post, A 
strikes the lever B, 
and causes the sig- 
nal C, which is 
provided with a 
lamp for night sig- 
nals, to turn to danger, the lever B on being struck causes the 
wire or rod^D to move in a forward position, so that when the 



Fl Q. I EL EVATIO N . 



I40 



RAILWAYS AND LOCOMOTIVES. 



train reaches the lever E the signal is put to " All right." F 
are the rails. 

2. The next self-acting apparatus we shall describe is in- 
tended to be fixed on the side of the permanent way. 




Fig. I is a front view, showing all ready for the first wheel 
of the engine or carriage to press it down on the lever D. Fig. 
2 is an end view, showing other working parts of the appa- 



J^AILWAYS AND LOCOMOTIVES. 



141 



ratus, with the signal, fig. 4, attached to the lever P. Fig. 3 
is a top view. 

Suppose a train coming up to where a signal is placed. The 
wheel L in fig. i comes on the lever D, passing down which 
is a slide-bar, having a square or round hole K in the middle, 
a little lower down a cross-pin or the eye-lever, and at the 
bottom a joint for lever P. At S is a powerful spring to lift up 
the slide-bar C* When C is brought down, peg F is forced by 
the spring G under the hole K, and working the lever P brings 
the signal up for the next train. N is a strong elastic, fitted to 
take the sudden jerk which the engine would make. H is the 
eye-bolt for the peg to work in, I is to fasten wire, and J to 
plug or peg F. Suppose the train has passed over the lever D, 
down goes the bar C, in goes the peg F to the hole K, which is 
a great deal larger. The first signal is up, and now we come 
to the second, just similar to fig. i ; the wire JJ is attached to 
the wire J in the first one, and by passing over the second one 
works the lever M, withdraws plug F, and by the action of the 
powerful spring at the bottom, up comes the bar C on lever D, 
and down goes the signals, the one that we commenced with 
reacting for the next train to come to the second signal ; and 
the signalman can tell whether the first train has passed over 
the third apparatus by seeing whether the signal is down or not. 
The latter train cannot run into the other unless the signals are 
neglected. [There is considerable ingenuity in this idea.] 



Railway Brakes. — The following is perhaps more suited 
for goods than for passenger trains. It should be fixed on 
both sides of every 
truck of the train. . 

a is the cill of 
the truck, bb the 
irons connected 
with the wheels, c 
the rail to tie in 
the wheels, ^ is a 

stud on the brake of which ec swings, /is a lever in the centre 
of the truck, ^ is a spring to keep off the brake. In case of 
danger, the driver would tighten the wire-rope hk. This would 
raise the lever /, which would bring the ends of the brakes in 
contact with the rim of the wheels. These would lav hold of 




142 



RAILWAYS AND LOCOMOTIVES, 



the brake, and force it on so tightly that the wheels must skid. 
[This idea has not, we believe, been investigated with any- 
practical result.] 

Communication between Passenger and Guard. — Among 
the suggested means of arresting the attention of railway guards 
by passengers in the carriages, the following crude ideas have 
some claim to attention : — 

1. This consists of a circular tube, which is fastened in the 
interior of the panel which divides the compartments to the 
side of the carriage. 

AA is the side of the carriage ; B is a metal tube fastened 
to its inside, a spiral steel spring is contained in this tube, and 
fastened to a rod I. This rod has a metal plate D on one end, 

which secures it at C, 
and holds the spring 
back. On the other 
end of the rod a ham- 
mer head is fixed. 
When the knob E is 
pressed, it shoves the 
plate D from its place, 
when the force of the 
spring will send for- 
ward the hammer, 
which, striking on the 
bell F, placed on the 
outside of the carriage, 
would attract the at- 
tention of the guard. 
The hammer would 
remain outside, and the carriage where assistance was wanted 
be seen immediately. If any passenger used this " facetiously,'' 
the trick could at once be discovered, as the only part of the 
apparatus under the control of the passenger is the knob on the 
outside of the panel, as shown at G, and the spring could not 
be placed in its former position except by opening a small door 
in the panel, which would be kept locked. 

2. In the following plan, there would be the necessity of the 
guard's van being higher than the other carriages. There are 
other evident objections to the details. 





RAILWAYS AND LOCOMOTIVES. 



143 



By pulling the handle B you not only ring the bell, but also 
raise the alarm signal C to the position shown by the dotted 
lines. In the alarm 



Bd 



I 




W 



1, 



W. 





-^i 


f^>-- 


1 

GUARDS 






-^ 


r^^— 


■"— — I 


1 


i 






r 


1 


i 


1 


\ 






VAN 












w '^ 




^ © 



signal there is a 
piece of red glass, 
on which is painted 
the number of the 
carriage, which, 
when raised, ex- 
actly fits on the 
face of the lamp 

D, thus showing a red light. By this means the guard would 
be enabled to discover, either by day or night, the carriage 
from which the signal is made. 

3. Let every car- 
riage have a loud 
bell attached, with 
a rope and handle, 
or chain and handle 
from every com- 
partment, so that the pulling of the handle would cause the bell 
to ring, and so attract 
the guard's notice. Let 
the guard's van be built. 
a little higher than the 
other carriages, so that 
he could always have a 
full view of the train, and 
see when all was right. 

4. In this scheme the 
bells are done away with, 
and explosive signals 
substituted. 

Fig. I is the side view, 
AAAA are four common 
railway fog signals ; each 
one is coated, and made 
perfectly air-tight (glass 
would answer the pur- 
pose best), so as to pro- 
tect the powder from injury and moisture. These signals are 




144 



/RAILWAYS AND LOCOMOTIVES. 



shaped as shown in fig. 3, and made about the size of a small 
oyster. BB represent the sides of box in which the signals A 
are enclosed. CC are two square spouts or channels, leading 
down, one to each wheel — on the side of the carriage, on which 
the machine is fixed — as shown in fig. 2. These channels are 
just large enough to admit of the free passage through them of 
the signals A. DD is a self-acting guide, placed at the junc- 
tion of the two channels CC, and works on its hinge B. The 
upper portion of the guide DD is just weighty enough to cause 
it to rest in the position seen in the sketch, or in that of the 
dotted line. 

The lower part of the guide is a light square board hanging 
beneath the flooring of the carriage, and is acted upon by the 

rush of air when the 
FIC.2. _^ train is in motion. 

Thus it will be seen 
that the channel on 
the right or left hand 
side will be opened as 
the direction of the 
train may require. F 
consists of a lever, 
slide and spring, the 
working of which will 
shortly be explained. 
E is a wire, and may 
be connected with or- 
dinary bell handles in 
each compartment or 
to each seat if thought 
proper. The apparatus may be placed under the seat, or any 
part of the floor, but is best about midway between the two 
wheels. The box BB and the channels CC may be made of 
thin sheet metal. 

The working is as follows : — The bell handle G being 
touched, the lever F is operated upon ; the small slide N is 
withdrawn, thus releasing the bottom signal A, at the same 
time the spring M presses against the second signal A, and 
holds it in its place until the slide returns, when the second 
signal takes up the position of the first. The first signal A 
being now at liberty, passes down the left-hand channel C, and 




RAILWAYS AND LOCOMOTIVES. 



H5 



is delivered under the wheel, fig. 2, which runs over it and 
causes it to explode. This, as in the case of an ordinary fog 
signal, is accompanied by a loud report, which would call the 
attention of the guard and the whole train. In the foregoing 
description the train is supposed to be proceeding in the direc- 
tion of the arrow in fig. i. Should the train be going the 
opposite way, the guide DD would be reversed by the pressure 
of the current of air on the lower part of it, and would then lie 
in the position of the dotted line, thus opening the channel C 
on the right-hand side, down which the signal A would slide, 
and be delivered between the wheel and the rail as before 
described. The alarm may be repeated as long as there are 
any signals A in the box, 
which may be constructed 
to contain any number. 

One advantage to be 
claimed for this scheme is 
that no connection between 
one carriage and another, 
along the whole length 
of the train, is necessary 
to effect a comrnunication 
with the guard. 

5. The following plan 
suggests oral communica- 
tion between passengers 
and guard. It is proposed 
to place beneath the floor 
of each carriage a metal 
speaking - tube, connected 
between the carriages by a 
continuation of indiarubber 
tubing, coupled as shown 
in the annexed drawing, 
forming a line of commu- 
nication between the guard 
and driver at either end of the train, 
at each end with an alarm whistle. 

Each compartment of the carriages should be furnished with 
an intercommunicator, which would enable the passengers to 
communicate with the guard or driver through the same pipe. 
Across the mouthpiece in each carriage it is also proposed to 

K 




The pipe to be supplied 



146 



RAILWA YS AND LOCOMOTIVES, 



place a small clasp, secured by a seal (that must be broken 
before the apparatus can be used), which, by being the means 
of detection of, is therefore a security against, improper use. 

A, communicator, 
as seen in the car- 
riage ; B, intercom- 
municator under the 
floor of ditto ; C, 
screw coupler be- 
tween the carriages. 
To communicate, 
break the seal, pull 
out the pipe as far 
as it will come, and 
hold it so till your 
communication is 
complete, tell the 
guard the number of 
the carriage, then let 
the pipe return to its 
place by the action 
of the spring. 

Tramway Loco- 
motives. — The in- 
troduction of the 
tramway in the Lon- 
don streets will even- 
tually, we have no 
doubt, lead to the 
employment of the locomotive instead of horses. Messrs Ave- 
ling & Porter have adapted one of the road locomotives for a 
tramway at Mr Gray's Chalk Works, Essex, for the purpose of 
hauling up the excavated chalk to the docks. This engine we 
now describe. On the top of the boiler, easily accessible, is 
arranged the gearing. A pinion on the crank-shaft gears into 
a spur-wheel on a second shaft, from which motion is trans- 
mitted to the driving-wheels, four in number, by an endless 
chain. The engine is of ten-horse nominal; cylinder, 10 in. 
diameter, 12-in. stroke ; grate surface in fire-box, 7 J square 
feet ; number of tubes in boiler 60, each 2^ in. external 
diameter. There are two feed- water tanks, one under the coal 




RAILWAYS AND LOCOMOTIVES. 147 

tender, and the other under the front part of the boiler, holding 
collectively 350 gallons. The wheels are 4 feet diameter, with 
short tyres, coupled, as shown, with an endless chain, which 
can be tightened by an apparatus consisting of a slot in the 
main bracket, in which the bearings of the shaft can be raised 
and lowered. The cylinder is jacketed, steam being carried 
around it to the valve- chest. The boiler is fed by a pump 
worked by an eccentric on the crank-shaft. The fuel is carried 
in a coal-bunker formed on the foot-plate behind the fire-box, 
sufficient space being provided to accommodate from 10 cwt. 
to 20 cwt. of coal, according to the mode of packing. At 
Gray's the line leading from the quarries to the wharves is about 
a mile in length, and is laid to the 4-ft. 8|-in. gauge. At the 
quarries it divides into two branches, one having an incline of 
I in 36 to I in 41 against the traffic, the incHne being, more- 
over, situated where the line makes a series of reverse curves. 
The other branch has a steep incline where it leaves the pit. 
On the former branch the load of the engine consists of 15 
waggons, weighing about i;^ tons each, and each containing i;| 
tons of chalk, the total load being thus 45 tons, in addition to 
the weight of the engine. But the engine can take 20 loaded 
waggons up the bank, and a still heavier load has been hauled. 
On the latter branch the load of the engine consists of 15 
waggons, weighing i^ tons each, and each loaded with 2^ tons 
of chalk. Thus the load, exclusive of engine, is 56^ tons. As 
to economy, we learn that during one week the 2 engines 
formerly employed conveyed 3138 tons of material from the 
quarries to the wharves, with a consumption of 14 1|^ cwt. of 
coal, the fuel consumed being thus equal to 5 lbs. per ton drawn. 
On the other hand,' two of Messrs AveHng & Porter's engines 
transported during corresponding week 5100 tons of material, 
with a consumption of 125 cwt. of coal, the expenditure of fuel 
being in this case equal to about 2| lbs. of coal per ton hauled. 
It is estimated that this difference in the quantity of coal required 
to perform a given work will save the company upwards of £1^0 
per annum. Altogether, these engines have given abundant 
evidence of being well adapted for use in quarries, and wherever 
heavy loads have to be moved at slow speeds — doing the work 
at about half the cost of horse-power. The engines can also be 
employed to drive portable or fixed machinery. All the wheels 
being coupled, the whole weight is available for producing adhesion 
to the rails, which is sufficient for the requirements of such lines. 



148 



FIREARMS, 



Wheel Grrease. — Nothing is equal to tallow for large cog- 
wheels ; but a good grease may be made of tallow 25 pounds, 
tar 25 pounds, soda 1 5 pounds, and water 3 or 4 gallons. Boil 
the soda and water till the former is dissolved, then add the 
other ingredients, and boil till thoroughly mixed. 

Rifle Stadia for Judging Distances. — An apparatus of the 
kind, for rifle practice, patented by Mr D. M ^Galium, has been 
approved and extensively used in some districts. 

1. Place the butt of 
the rifle on the ground, 
with the toe of it to- 
wards the right. 

2. Then place the 
piece of metal in muzzle 
with end marked * Foot' 
upwards, if the distance 
of a man be required. 

3. If the distance of 
a man on horseback be 
required, place the end 
marked * Horse ' up- 
wards. 

4. Steady rifle with left hand, and with the finger and thumb 
of the other hold the tape closely to the eye on the cheek-bo7ie. 

5. Then look at the object through the 
aperture, and slide the face along the tape 
until the eye definitely and completely 
covers the feet of the man and the top of 
his cap, or the hoof of the horse and the cap 
of its rider. 

6. Now observe the mark on the tape 
where the finger is, and it will show the 
number of yards distant. Thus : Should the 
finger appear at the first subdivision beyond 
100, the distance would be iio; if at the 
second subdivision, it would be 120 yards, &c. 

7. Should the object be more than 350 
yards off, it will be necessary to screw the 
ramrod in the centre of the piece of metal, 

and steady the rifle with the ramrod by holding it securely 
and keeping the tape at its full tension ; then proceed as before. 




900 yards. 




100 yards. 



FIREARMS, 149 



Gun Cotton. — The following is stated to be the best and 
simplest process for making gun cotton. Saturate some cotton 
wool in a solution of equal volumes of the strongest oil of 
vitriol and nitric acid for a few minutes, then express the 
superabundant liquid out of the cotton, and wash it in cold 
water until all taste of acidity has gone ; lastly, dry at a gentle 
heat, about 120° or 130°. 



Force of Gunpowder. — When gunpowder is heated nearly 
up to the point of decomposition, previously to ignition, the 
force of its explosion is greatly increased. It is stated that a 
temperature of 160° Fahr. increases the force of the explosion 
I- 5th, while a temperature of 400° nearly doubles it. This 
may in some measure account for the fact that highly-heated 
guns are liable to burst if the charge has been allowed to 
remain in the chamber a sufficient time before firing. 

Gun Barrels. — To Bore. — Take a piece of rod, cast steel, 
J in. smaller than the interior of the barrel and a few inches 
longer, beat one end up something larger than the size of bore, 
then turn or file it the shape of an egg, leaving the swell or 
centring part i-20th of an inch larger than the bore. With 
a saw-file, cut longitudinal cuts \ in. apart, laying them the 
same angle as a rose-bit countersink, taking care not to injure 
the periphery of the tool ; harden, and temper to straw colour. 

Staining, — Spirits of wine i oz., tincture of steel i oz., 
muriate of mercury \ oz., nitric acid \ oz., and water i quart. 
The above mixture must be well incorporated before use. 
Process, — i. The grease to be removed by coating the gun 
with lime, put on in a thin paste, and allowed to dry, then 
brushed off with a clean hard brush. 2. The mixture to be 
laid evenly on the gun with a sponge, and allowed to stand till 
dry. This operation to be repeated as frequently as the gun 
dries, for the first ten hours, then the rust to be thoroughly 
scratched off with wire cord. 3. Coat with mixture, and let 
it stand till dry ; if the gun rusts freely, no more mixture need 
be applied, but that already apphed may be scratched off with 
wire cord at the end of ten hours if dry ; but if it should rust 
slowly, then one or two extra coatings of the mixture may be 
laid within the ten hours, taking care that the old rust is dry 
before again applying the mixture. 4. As soon as the barrel 
is dark enough, it must be immersed in boiling water to kill 



ISO HOROLOGY. 



the acid, and then oiled with olive oil while warm ; then remove 
the oil with turpentine, and varnish with copal varnish. 

Browning, — Equal parts of butter of antimony and olive oil 
to be rubbed on while the barrel is hot, expose to the air till 
sufficiently brown, clean carefully, and coat with a thin shellac 
varnish. Butter of antimony is a powerfully corrosive poison, 
and must therefore be handled with care. 

Colouring, — First clean the barrel perfectly, but do not touch 
it with the hands. To avoid this, put a stick or plug into the 
end of the barrel to hold it with, then apply the following mix- 
ture with a rag (not too much at a time, if a twisted barrel, as 
you will not be able to get the twist to show properly). After 
the colour-matter gets dry, it must be rubbed off with a steel- 
wire brush. For a plain barrel — \ oz. nitric acid, ^ oz. spirits 
of nitre, 2 oz. sulphate of copper, i oz. tincture of steel, 8 gills 
of water. For a twisted barrel — \ oz. spirits of nitre, \ oz. 
tincture of steel, \ oz. sulphate of copper, 1 5 grains of mercury, 
1^ pint 6f water. After having stained the barrel apply the 
following polish : — 2 oz. spirits of wine, \ oz. gum Benjamin. 
Put it on with a soft rag or camel-hair brush : use it quickly, 
or it will dry very fast. 

The Verge Escapement. — Every one who wears a watch 
should know something of its mechanism. He would then be 
better enabled to take care of it, and set it right when it went 
wrong. There are three kinds of escapements used in modern 
watches — the Verge, the Horizontal, and the Lever. The first 
is the oldest, and in some few respects the best. The parts 
of a verge are the cock and foot pallets, also cock and foot 
■ pivots, and the " collet, ^^ or piece of brass soldered on to the 
top, and to which the balance is riveted. The parts of a pinion 
are the leaves or head, the arbor, and the pivots or bearings. 
The parts of a wheel are the teeth, the rim, and the cross ; if 
the wheel is not riveted on to the head of a pinion, a " collet " 
is driven on to the arbor, and to which the wheel is riveted. 
The escapement is the term used to illustrate the action of the 
pallets in connection with the last or scape wheel, one tooth of 
which escapes at each vibration of the balance. The crown- 
wheel or verge escapement was the first invented. Fig. i 
shows how it is arranged in a watch. B is the balance, the 
axis of which is the verge ; P^ is the cock pallet, and P is the 



HOROLOGY. 



151 




foot pallet ; the top or cock pivot runs in the cock C, and the 
bottom or foot pivot in the potance X. S is the hair-spring 
and stud. The scape- wheel O, also called the balance-wheel, 
is riveted on to the head of the pinion ; the pivot inside the 
wheel runs in a dovetail fitted into the nose of the potance at 
N, this dovetail is made to slide in and out, so as to get the 
hole opposite the body of the verge, or the escapement equal ; 
the pivot at the other 

end of the pinion runs fig . 1 . 

in a hole in the follower 
F, which is fitted into 
the counter - potance. 
The contrate-wheel W 
is not riveted on the 
pinion, but has a " col- 
let" on the arbor to 
enable it to work into 
the scape-pinion. The 

teeth and rim are contrary to those of other wheels, whence it 
takes its name. Fig. 2 shows the details. X is the potance ; 
T is the counter-potance, which is riveted into the top plate, 
and into the hole of which the follower F is fitted ; V is the 
verge with the '' collet '' turned down to fit the balance ; Z is 
the hair-spring ** collet ; '' B is the balance; S is the hair- 
spring stud, the outer coil of the hair-spring is pinned into 
the stud, and the 
inner coil is pinned 
into the " collet,'*' 
which fits spring- 
tight on to the 
verge collet and 
close up to the 
balance, and can 
be set to any place 
by turning it round 
on the verge with a 

screw-driver put into the notch ; D is the regulator, fitted into 
a slide so that it can move in a circle having the verge as a 
centre, the end of the regulator projects under the outer coil of 
the spring, and has two small pins rising up from it, and 
between which the spring plays. The effective length of the 
spring can thus be altered by moving the index to fast if the 



^ 








152 



HOROLOGY, 



watch loses, and to slow if it gains. If the regulator is at fast 
or slow, and the watch continues to gain or lose, the spring 
must be altered from the stud, that is, more spring let out if 
gaining, and if losing more spring taken up. To do this, put 
a bristle into the cross of the contrate-wheel to prevent it run- 
ning down; then take off the cock C (Fig. i) and unpin the 
spring out of the stud with a pair of tweezers, take out the 
verge and turn the collet round with a screw-driver in the 
direction to bring more or less spring through the stud as the 
case requires ; having done this, replace the verge, join in the 
spring, and put on the cock again. Then try if the watch is in 

beat ; thus, suppos- 
ing the balance is at 
rest and the banking 
pin at B, if the con- 
trate-wheel is pushed 
round slowly and 
steadily with the 
thumb, the pin will 
be drawn first to A 
and then to C if the 
watch is in beat ; 
if it is not, the 
"draw^' will be more 
to one side than the 
other ; if C has most 
draw the spring must 
be let out a little, 
and if A has most 
the spring must be 
taken up a little. 
We must now ex- 
plain the action of the escapement. The verge pallets are 
nearly at right angles ; the scape-wheel has always an odd 
number of teeth, so that a tooth on one side is opposite a space 
on the other, and when one pallet is in action the other is out 
of action. Fig. '3 is a sketch of two escapements, the teeth of 
the wheel and the pallets are enlarged. The wheel must be 
supposed to be turning on its axis with the teeth i and 2, and 
the cock-pallets P' P' at the top, and the dotted teeth and the 
foot-pallets P P at the bottom. Tooth i has just escaped from 
and given impulse to the pallet P', and the dotted tooth has 




FIG ^ 




^^ \^^ 


'--oy 


^^^ 


1 


2* 









HOROLOGY, 153 



dropped on to the pallet P, the balance B is ^* vibrating " or 
turning in the direction of the arrow, and will continue to do 
so until the impulse is exhausted by the bending up of the hair- 
spring and the " recoil " or backward movement of the wheel 
produced by the dotted tooth opposing the pallet P ; the balance 
will now be brought back by the tension of the hair-spring ; the 
dotted tooth will then give impulse to and escape from pallet 
P, the next tooth dropping on to pallet P^, as shown by tooth 
2 ; the balance B^ is vibrating in the direction of the arrow, 
tooth 2, opposing pallet P^, producing the recoil as before. It 
will thus be seen that two contrary vibrations of the balance 
take place before a tooth has completely escaped. The bank- 
ing is to prevent the balance turning round too far, in which 
case the pallet would be turned away from the wheel, which 
would of course run down with great force, and break its teeth 
by striking against the pallets when they turned round again. 
The best banking is a pin in the balance at B, and therefore 
moving in a circle round the edge of the cock C, fig. i, which 
covers the balance. The extent of the banking is determined 
by the pin meeting two projecting parts of the cock which 
reach beyond the circle the banking-pin moves in. The bank- 
ings are made as wide as possible, and for the teeth to have a 
fair hold on to the pallets. Thus, supposing the banking-pin 
is turned by an accidental jerk to B, fig. 4, the dotted tooth i 
will act on pallet P, and bring the balance round again ; and 
if the banking-pin is at B^, the tooth 2 will act on pallet P% 
and bring the pallets into action again. The great defect in 
the verge escapement is the " recoil," the wheels being carried 
half as far back as they have advanced, consequently the verge 
and dovetail holes wear very wide, and when so worn the 
watch cannot go well ; the constant rubbing of the wheel-teeth 
on the pallets wears the verge out, and also the tops off the 
wheel-teeth, not all alike, but very irregular ; hence the wheel 
often requires topping or recutting. The nose of the potance 
must be filed to let the wheel up closer, and then the counter- 
potance filed away to let the follower up, or, what is much better, 
a new follower must be made. The verge escapement could be 
constructed much better, but as it is now nearly superseded by 
the lever escapement, no improvements are likely to be adopted ; 
but as there are a great many verge watches in use, a knowledge 
of the escapement is still required to keep them in repair. 



154 



HOROLOGY, 



Four-Legged Clock Escapement. — The following are the 
particulars of Mr Denison's Four-legged Gravity Escapement 
for regulating clocks : — 

Fig. I is a view of the escapement, looking at the back of 
the clock. Fig. 2 is a section of the escapement and part of 
the train of wheelwork. The letters refer to the same parts in 

both figures. EF is the scape- 
wheel of a diameter of three 
inches, the acting faces of the 
four teeth being at right angles 
to each adjacent one. On the 
central disc of the scape-wheel 
are set eight pins, four pointing 
one way and four the other. 
These pins are \ of an inch 
from the centre of the wheel, 
and one set of four are to be 
placed on a line with the act- 
ing faces of the teeth, and the 
remaining four equidistant be- 
tw^een them. 

A,B,C,D are the pallets which 
are lifted by the pins of the 
scape-wheel acting on the arms 
LM. The stops on the pal- 
lets are show^n at GH, and the 
proper placing them requires 
a little attention. In drawing 
out the escapement, the scape- 
w^heel should be placed within 
both as at E, and the next 
look will show the proper 
place for the stop H to be 
screwed to the pallet CD. 
The stop G must be placed 
a little higher than the stop 
H. The distance of the pallet 
arbors from the scape-wheel centre is 3-5 inches, the arbors 
being placed as near the vertical line as possible, to avoid fric- 
tion. The pallets are prolonged until they meet the pendulum- 
rod, as shown at B and D. The whole of this escapement 




HOROLOGY. 155 



should be made of steel. The weight of the pallets must be 
made such as to cause the pendulum to swing an arc of 4 de- 
grees. A very material feature in this escapement is the fly 
IK, which is attached to the scape-wheel arbor by a piece of 
watch-spring in the usual manner. The object of this is to 
prevent what is called tripping, that is, the pallets A, B, C, D 
being thrown out too far by the scape- wheel turning too quickly. 
The fly is large, measuring in total length 4 in. by i in. broad. 
It will be seen by fig. 2 that the pallets are not in the same 
plane, but that the scape-wheel turns between them. One stop 
is placed on the front of one pallet, and the other on the back 
of the other pallet. We will note the numbers of the teeth of 
the wheels and pinions, which will, we think, be found most 
desirable. 

Wheel No. i. 120 teeth drives pinion of 10 teeth or leaves. 

2. 80 „ 10 

3. 75 „ 10 

4. 75 ,, 10 

The great wheel No. i had better be at least |- of an' inch 
broad on the edge, because these clocks take a heavier weight, 
about 25 lbs., for a regulator. These clocks have only been 
made with second pendulums so far as we know, and it may 
be convenient to state the times of revolution of the various 
wheels. 

The scape-wheel turns once in 8 seconds. 
Wheel No. 4 „ 60 seconds. 

3 „ l\ minutes. 

„ 2 ,, I hour. 

„ I „ 12 hours. 

It is perhaps hardly necessary to remark that the acting sur- 
faces of the various parts of the escapement must be left as 
hard as they safely can be. It is essential that the fork-pins 
of the pallets B and D should be so adjusted, that as the pen- 
dulum-rod comes into contact with one it just leaves the other. 
For the reason of this, and for a great variety of information 
respecting gravity escapement, we refer our readers to Mr 
Denison's book, certainly one of the most scientific and valuable 
yet produced on its special subject. 

But for the information of those to whom the book is not 



156 



HOROLOGY. 



accessible, we may explain the action of the escapement. At 
present one leg of the scape- wheel is resting on the stop H ; 
the pendulum P is swinging, as shown by the arrow, to the 

right, and will 
carry with it the 
pallet CD. As 
soon as the stop 
H is lifted out of 
the way of the 
scapewheel tooth, 
the wheel acted 
on by the clock- 
weight will turn 
until the tooth N 
is arrested by the 
stop G, and dur- 
ing this motion of 
the scape - wheel 
the pallet AB will 
be lifted by the 
pin in the scape- 
wheel a little out- 
wards to the left, 
and it is by the 
weight of the 
pallet AB acting 
through the fork- 
pin at B onthe pen- 
dulum - rod from 
that point to which 
the pallet is lifted 
by the scapewheel 
to that pointwhere 
the pendulum 
leaves it that half 
the impulse to the 
pendulum is sup- 
plied. The pallet 
CD on the other side contributes the other half in a similar 
manner. It will be observed from fig. 2 that the great wheel 
No. I, on the arbor of which is placed the barrel for the weight 




HOROLOGY. 



157 



cord, is at the top of the frame. This arrangement was almost 
unavoidable with some of the early forms of the gravity escape- 
ment, but it will be much more desirable to have the great 
wheel at the bottom of the frame, and with this form of the 
escapement there is no difficulty about it. We recommend 
any one before commencing the actual construction to make 
fair working drawings of the clock. 



2 C6-> 



r\ 



4 



6 



Compensating Pendulum. — The follow- 
ing is suggested by a practical watchmaker as 
a good plan for a compensation pendulum. 

1 is the back cock attached to the clock frame. 

2 to 4 is the pendulum-rod of flat iron, the 
middle rod riveted fast to it at 4, and the 
outside rod riveted to the middle one at 5. 

3 is the crutch that works the pendulum. 
6 is a screw fast to the pendulum-rod to 
steady the middle rod, but loose in the 
middle rod to allow it to expand. 7 is a 
screw fast to the middle rod to steady the 
outside rod, but loose on outside to allow it 
to expand. 8 is the pendulum ball of iron 
on the outside rod. As the rod from 2 to 

4 expands downwards, the middle rod from 
4 to 5 expands upwards, and keeps the pen- 
dulum-ball in the same position. 

The Chronometer Escapement. — The chronometer escape- 
ment is undoubtedly the best timekeeper, the reasons for which 
are — i. The '* impulse'^ is given to the balance " directly " by 
the scape-wheel without the intervention of a lever or other 
obstructing mechanism. 2. The impulse is given in the most 
favourable manner, ** across the line of centres," and will thus 
carry a heavier balance. 3. The escapement is more completely 
detached, hence the isochronism of the balance vibrations are 
not as much disturbed. The chronometer escapement is thus 
admirably suited for marine timekeepers, or box chronometers, 
as they are called, and which are hung in gimbals in a square 
box like a mariner's compass. The dial is thus kept always 
horizontal, and the balance is also kept in one position, that is, 
working on the cock pivot. The movement is also kept very 
steady. 



I 



158 HOROLOGY. 



The case is very different with a pocket-watch, which has to 
go in every position, lying up or lying down, and is also sub- 
jected to jerks and shakes by the most careful wearer in pulling 
it out of the pocket to see the time, to say nothing of the shakes 
and changes of position while it is in the pocket, and the treat- 
ment it may get from a careless wearer. A chronometer 
escapement, therefore, with its heavy balance, is not suited for 
a pocket-watch. Another objection is that the impulse is given 
in the one direction only, the unlocking taking place on the 
return vibration, which receives no impulse ; hence if the watch 
gets a sudden shake in a contrary direction to the way the 
balance is vibrating, the unlocking will be prevented, and the 
watch will stop, and will require a good shake to start it again, 
and also if it is let run down must be shook after winding to 
start it. The escapement also requires great accuracy of con- 
struction, and is otherwise unsuited for rough use. 

In the lever escapement the impulse is given at every vibra- 
tion by the scape-wheel to the lever, and by the lever to the 
balance. If the escapement is made in the proportions it will 
not " set," hence will not be affected materially by a sudden 
shake, neither will it require to be shook to start it on winding 
it up after being run down. The ordinary lever escapement 
does not require such extreme accuracy of construction, and is 
therefore cheaper and better suited for rough use, and will keep 
time to within a minute a week, which is near enough. 

The two-pin lever escapement is considered the best form of 
lever escapement, but it is thought by many to be not so good 
as a timekeeper. 

A watch, like a steam engine, must be kept in good order. 
A steam engine cannot be let run long without oil, but will 
report its sure wants in a manner *• not to be mistaken,^' and 
a labourer using a wheelbarrow must for his own comfort 
attend to the ^' screeching" of the wheel. The trains given to 
lever and other good watches showing seconds are 14,400, 
16,200, or 80,000 vibrations or beats in an hour: each 
" vibration " means a '' revolution " of the balance. Now, 
either of these sums x 24 x 365 will give the number of beats 
or work done in a year. The slowest — 1 4,000 — gives 
126,144,000 beats in a year. A moment's attention to this 
fact will convince readers that, although the oil used for 
watches is the best we can get, and may not congeal, yet it 



HOROLOGY. 



159 



must be all used up in a year or eighteen months ; and then 
if the mainspring and great wheels are powerful enough to 
keep the watch going, the pivots and other actional parts must 
and will wear out — in silence, of course, for watches do not 
" screech ^^ like wheelbarrows. 



Double-Roller Escapement. — The lever-watch double-roller 
escapement is very similar to the ordinary kind of lever escape- 
ment with the table-roller, but may be distinguished by its 
having an additional, though small, roller below that which 
holds the ruby-pin. The ruby-pin is fixed in the main-roller 
in the usual way, and serves the same office as that generally 
known ; but as the guard-pin has no connection with it, the 
piece carrying the ruby-pin is frequently formed of the shape 
of an arm, the steel disc being for the most part filed away, 
leaving only sufficient to secure 
hold the ruby-pin. Thus, then, 



it to the balance-staff, and to 
this part might be called an 



arm 



, carrymg 
Underneath 




the ruby- 
pm. unaerneath this is 
fixed another roller, rather 
small, having a hollow 
filed out similar to that 
which is generally noticed 
in the ordinary table-roller, 
the object of which is to 
allow the guardpiece to 
pass as the passing hollow 
in the table-roller admits the passing of the upright guard-pin 
in the lever. Looking at the two rollers together when properly 
fixed, a person acquainted with the crank-roller might think that 
one and the same object only was achieved ; but it is not so. 

Without referring to the crank-roller further, let it be under- 
stood that the only purpose of the second-roller in the double- 
roller escapement is to serve the purpose of the safety action. 
This is accompHshed by having a pin bent at right angles from 
the under side of the lever, so as to reach sufficiently far to 
ensure a sound guard-pin depth. So that, in reality, the main- 
roller is a radial arm carrying the ruby-pin ; then to secure a 
sound guard-pin depth the small roller is placed below, and the 
bent guard-pin projects sufficiently long to ensure safety of the 
escapement. 



i6o HOROLOGY. 



The annexed diagram will assist in the description : — A, 
main-roller, carrying the ruby-pin ; B, the lever ; C, the bent 
guard-pin ; D, the second or safety roller. The balance- staff, 
of course, passes through both. 

To Restore Watch Dials. — If the dial be painted, clean 
the figures off with spirit of wine, or anything else that will 
render the dial perfectly clean ; then heat it to a bright red 
heat, and plunge it into a strong solution of cyanide of potas- 
sium ; then wash in soap and water, and dry in box-dust. 
Repeat if not a good colour. Indian ink ground with gum- 
water will do for the figures. 

Blight's Perpetual Motion Electric Clocks. — Several of 
these clocks have been in use for four or five years without 
intermission; An account of them will, therefore, be interest- 
ing. Presuming that our readers are acquainted with the 
general principle of electric clocks, the following account will 
be understood by referring to the engravings : — In fig. i WW 
are the wires leading to the two poles of the battery. The 
wire W is attached to the bracket ^, and the current passes 
down the suspension of the pendulum, and by a wire, shown 
by a dotted line, down the wooden stem of the pendulum, then 
round the coil of wire in the bob of the pendulum, and up the 
wire on the other side, also shown by a dotted line, to the 
touching-plate P, and through the leg L of the brake, and off 
by the wire W to the other pole of the battery, thus completing 
the circuit when the pendulum is in the position shown in 
fig. I. 

The bob of the pendulum is thus for the instant converted 
into an electro-magnet. The tube M is fixed to the clock-case, 
and contains permanent magnets, which of course attract the 
electro -magnet in the bob of the pendulum, which thus receives 
a little additional impulse at every alternate stroke. By the 
time the pendulum arrives at the other side, as in fig. 2, it has 
in its journey moved the break B, so that the little balance- 
weight T has fallen a little past the centre on the other side, 
and so has brought the leg L' in contact with the piece of 
glass G on the stem of the pendulum, and has thrown the leg 
L clear of the touching-plate P, and has thus broken the cir- 
cuit. The pendulum then makes the return stroke by its own 
weight, when contact is again made, and so on. 



HOROLOGY. 



i6] 



By fitting a double break to the pendulum it receives an 
impulse at every stroke, instead of every alternate stroke. 

It will be observed that the break consists of the two long 
copper legs L, L^, and the balance-weight T, all mounted on a 
triangular piece of ivory which moves on the pivot p. The 
friction of moving this break is obviously very little ; it is, in 
fact, so little that 



F1C3 



FIC 2 



one piece of zinc 
and one piece of 
coke buried in the 
ground afford a cur- 
rent of electricity 
sufficient to drive 
eight or ten or more 
of these clocks for 
a lifetime. 

Another feature 
in this break is that 
the legs move in an 
arc of a different 
radius from that in 
which the contact- 
plates move ; conse- 
quently at each time 
of touching, the con- 
tact - plate receives 
a slight rub^ which 
wipes off any dust, 
and ensures a per- 
fect contact. 

The wires W and 
W, on their way 
to the poles of the 

battery, may communicate with and work other clock-dials. 
These affiliated clocks are by preference made with pendulums, 
because if the current misses its errand once or twice, no harm 
is done, as each pendulum has sufficient momentum to work 
its own clock for three minutes without assistance from the 
battery. 

In the Continental system of electric clocks the affiliated 
clocks have no pendulums, but are actuated by a powerful cur- 

L 




1 62 



HOROLOGY, 



rent from an acid battery once in a minute. Thus, if by any 
mischance a clock '^ misses a pegl' it is a minute slow at once. 

Under Mr Bright's system the 
pendulums of all clocks in con- 
nection are vibrating together, and 
are in fact always parallel to each 
other. 

A set of four clocks, worked from 
one piece of zinc 2 ft. square and 
one piece of coke, have been at 
work at Leamington for two years ; 
and though they were only a trial 
set, not over well made, they have 
never deviated from mean time more 
than a few seconds per week, and 
have never deviated from each other 
at all. The said piece of zinc and 
coke have been in use during the 
twenty years in which Mr Bright 
has been engaged in perfecting his 
invention, and on the occasion of a 
visit from a gentleman from Green- 
wich Observatory for the purpose of 
inspecting these clocks, the zinc and 
coke were dug up and found to be 
apparently as serviceable as ever. 

An interesting fact, in connection 
with this part of the subject, is that 
a set ' of three clocks are at work 
with no other battery than one wire 
attached to a gas-pipe and the other 
to a piece of coke. 

Also another pair of clocks are at 
work with one wire attached to a 
water-pipe and the other to a piece 
of coke. A set of five clocks may 
be seen at work at the Gun Cotton 
Office, 173 Fenchurch Street. 
It is thus evident that these clocks 
require very little power to keep them in motion, and have 
very little friction, and it may be expected that the liability to 




HOROLOGY, 163 



error will be proportionally diminished ; and therefore much 
may be hoped for them in the direction of good time-keeping, 
as well as uniformity, both great desiderata for railway and 
commercial purposes. 

Several years ago Mr Gammage invented a mercurial pen- 
dulum with the rod passing entirely through the mercury. 
This pendulum is used for timing compensation work, so that 
accuracy is indispensable. The springing of a pendulum is a 
matter that requires much greater attention than it generally 
receives. Many well-made pendulums are badly sprung, and 
give off unsteady rates when put to first-rate movements. The 
following is the description of the instrument : — 

A, steel rod passing through tube ; B, tube to which lower 
cap is attached ; C, glass jar to hold mercury ; D, regulating 
nut, working on screw cut on lower end of rod. 

The jar has a hole cut through the bottom rather larger than 
the tube, the outer edge is carefully ground into the cap, and 
when the pendulum is finished it is set with cement. 

Mercurial Pendulum. — Fig. i represents a pendulum, with 
a stirrup to support the glass jar. The rod is steel, and about 
4-ioths wide by 2-ioths thick. The spring at the top is \ 
in. wide, and 2 in. long. The sides of the stirrup are steel, 
the same size as the rod, and are joined at the top with two 
steel plates. There are also two short pieces of the rod steel 
put between the plates and close up to the rod, to form a groove 
for the rod to slide in, the whole being pinned and screwed up 
together as shown. The bottom of the stirrup is a circular 
plate of brass, hollowed out to fit the bottom of the jar, and 
has two forks to fit the steel sides, and through which the 
screws are put, as shown at D. There is also a brass cap 
fitted to the top of the jar, and with forks to fit on the steel 
sides ; but it is not screwed to them, so that it can be lifted up 
to put more in, or to take the jar out of the stirrup. The glass 
jar C is 2 in. inside, and i\ in. outside diameter, and 7|- or 8 
in. long. The height of mercury has to be about 6J in. ; but 
can only be got right by experiment ; no two pendulums are 
alike in this respect, as a great deal depends on the kind of 
steel used. One great advantage of the mercurial pendulum 
is, that it can be very readily adjusted. The length of the 
pendulum from the point of suspension A to the bottom of the 



1 64 



HOROLOGY. 



brass B is about 43 in. The bottom of the rod is made into 
a screw, and has a large milled and divided nut screwed on 
for regulating the clock. There is also an index screwed on 
to the plate to show how much the nut is turned 
I 1^1 round. The screw may be 20 to the inch, and 

riG.i the nut divided into 50, so that if the nut is 
turned round one division, it will raise or lower 
the stirrup one-thousandth of an inch. Having 
tried the clock to see how much it gains or loses, 
the following rule is given to ascertain how much 
to alter the nut, to bring the clock to time at 
once : — Multiply the theoretical length of the 
pendulum by 2, and by the number of seconds 
gained or lost in a day, and divide the result by 
the number of seconds in a day ; the quotient 
will give the parts of an inch by which the pen- 
dulum must be lengthened or shortened. The 
theoretical length of a seconds pendulum is 
39*2 in., and the seconds in a day 86,400". 
Now suppose the gain of a seconds pendulum 
to be three minutes per day, we have 39*2 x 2 
= 784 X 180^''=: 141 120 4- 86400 = -163 parts 
of an inch, that is, three turns and 1 3 divisions 
of the nut by which the pendulum is to be 
lengthened ; if the clock had been losing, of 
course the pendulum would require to be short- 
ened. Mr Denison says, in his work on 
" Clockmaking," if the screw is 16 to the inch, 
and the rod 43 in. long, one turn of the nut will 
alter the clock one minute per day ; so that if the nut is divided 
into 60, one division will alter the clock a second a day. Cold 
weather is the best for adjusting compensated pendulums, as 
the temperature of the clock-room can be 
raised by fire or gas, and lowered by letting 
the fire out. To adjust the mercury, let 
there be only 6 in. in the jar, and regulate 
the clock in the cold room, so that it has a 
losing rate of say five seconds a day; now raise 
the temperature, and note if the clock loses 
still more, if so, more mercury is required : put in a little : now 













© 






1 

m 







\ 




J 


\m 




C 


fe 




© 



Fig. 2. 




see what the rate is, and then lower the temperature, and see 



HOROLOGY, • 165 



if the rate is the same. If the rate is less when the temperature 
is lowered, put in some more mercury, and again note the rate 
and raise the temperature, and see if the rate is altered, thus 
repeating the process until the rate is the same, as near as can 
be, in heat and cold. The final adjustments had better be left 
perhaps for summer and winter, as long- continued experiments 
and observations are required to obtain satisfactory results. 
Adding to the mercury will reduce the original rate five seconds 
a day, so that the clock will be brought to time without altering 
the nut at the bottom of the rod ; of course, if the nut has to 
be altered, the compensation will have to be adjusted again. 
Unless the clock is a good one, perfect in all other respects, it 
is not worth a compensated pendulum. 

Reducing Hair-Springs. — Hair- springs may be reduced by 
rubbing them down on a flat oil-stone with spirits of wine 
instead of oil. Use the middle finger, giving a circular motion 
to the hand while rubbing, and let the pressure be even, but 
not too hard, or the spring may get injured. If the watch 
gains more than five minutes a day, it will be less trouble to 
put in another spring. The strength of the springs can be 
tried by weighing the balance with the spring, thus : Lay hold 
of the outer coil of the spring in the tweezers, and ''' hook " the 
inner coil on to the foot of the verge or cylinder, and lift the 
balance up, the spring will thus be pulled down into a " taper 
spiral ; '' the weak springs will, of course, have longer spirals 
than the strong ones. Lever staffs must have a bit of wax or 
pegwood stuck on to the foot pivot, and to which the spring 
can be hooked. The strength of spring required depends on 
the diameter and weight of the balance, and the number of 
beats or vibrations per hour, technically called the " train." 
The only way to tell if a spring is the proper strength is to put 
it on the watch and try it. The springs are sold sized in dia- 
meters and strengths, and if we could get the balances sized in 
diameters and weights, after a few experiments we should be 
able to select the proper spring at once. The results of experi- 
ments should be entered in a book for future reference thus: — 



1 Train. 


Balance. 


Spring. 


1 16,200 


Weight. 
10 


Size. 
10 


Strength. 
10 


Size. 
10 



i66 HOROLOGY. 



This method is proposed for plain balances only ; for superior 
watches, with compensated balances, the isochronism of the 
hair-spring has to be ascertained. 

Strength of Mainsprings. — The reason a verge watch 
gains when the strength of spring is increased is that the 
balance is always connected with and influenced by the main- 
spring or maintaining power. Thus, when a tooth of the 
scape-wheel has given impulse and escaped from one pallet, 
another tooth drops into the other, and by the " recoil" exerts 
the full force of the spring to shorten the vibration, and thus 
makes the watch go faster. The horizontal escapement is used 
in Geneva watches, and to this escapement the impulse is given 
by the oblique faces of the table acting on the edges of the 
cylinder as they pass out. The teeth, after giving impulse, 
drop on to the outside and into the inside of the cylinder alter- 
nately, and remain " dead " during the vibration. The impulse 
is given when the balance is near the quiescent point, and the 
balance is then left to finish the vibration by the combined 
action of the hair-spring and its own momentum, without being 
influenced by the maintaining power. If a stronger spring is 
put in, the impulse will be more intense, and would cause the 
balance to vibrate quicker; but the '^ friction '' of the teeth on 
the inside and outside of the cylinder is also increased, and 
thus counteracts the extra strength of the mainspring. It will 
thus be seen that a fusee is not required to equalise the power 
of the mainspring, as the watch will keep the same time within 
moderate limits whether the spring be weak or strong. In 
verge watches, on the contrary, a fusee is an absolute necessity, 
and the spring must also be " set up," so that it is as strong at 
the bottom as it is at the top. For this purpose watchmakers 
use an " adjusting rod," which is a steel rod with sliding 
weights upon it, and a pair of jaws to secure on to the fusee 
square. The rod can be bought at the tool-shops for about 
IS. 6d. To adjust the mainspring the watch is put together 
without the third wheel, and is held in the left hand edgeways 
with the fusee and barrel at the top. The rod is secured to the 
fusee square with the weights at the bottom. The watch must 
now be wound up, and the weights moved along the rod until 
the spring will just pull the rod " over." The right hand must 
be kept in " front " of the rod, and thus ease it over, for if it is 



HOROLOGY. 



167 



let go over too sudden it will break the chain. Having set the 
weights so that their " leverage " and the strength of spring 
when wound up are counterpoised, the watch is let down and 
the spring " set up " until it will pull the rod over with the 
same force as it did when wound up, or as near as can be, for 
if the fusee is not long enough and of the right shape, it will 
not be possible to get it exact. In marine chronometers the 
shape of the fusee is altered until the force is equal in every 
turn, but such extreme accuracy is of course unnecessary in 
pocket watches. The strength of spring required depends on 
the size of the watch, and also whether it is in perfect repair or 
not. When the holes and pivots are worn, the wheels often 
rub each other, especially in thin movements ; and if new holes 
are put in, it is seldom the wheels are so free or the depths 
(pitchings) so good as they might be, hence a stronger main- 
spring is required to pull the watch along. The strength of 
the springs depends on their breadth and thickness taken 
together, but should be as wide as the barrel will allow without 
rubbing the cover, and must not be too thick, or they will not 
make turns enough in the barrel. To ascertain the number 
of turns required, 
wind the chain on 
the barrel and 
count the turns, 
allowing half a turn 
for the spare end, 
which is not wound 
on the fusee. In 
verge and Geneva 

watches four effective turns are required ; and if we allow half 
a turn for ^' setting up," the spring must make at least 4f turns 
in the barrel. To do this, the spring should occupy one-third 
of the barrel, the arbor one-third, and one- third space. In 
lever watches the barrels are smaller, and the spring should 
make 3|- turns in the barrel. Most lever watches have a fusee, 
but do not require adjusting ; in fact, the fusee is too short to 
be correct. Above is a sketch of a mainspring punch made in 
a pair of common pliers thus : Drill a hole through both jaws 
from C to D ; tap a screw into C with the bottom end turned 
down for the punch ; chamfer the hole D with a taper-drill to 
free the punchings ; fit a bridge over the hole D between the 




i68 HOROLOGY, 



jaws, and file away the sides, so that when the spring is put 
through the bridge and pressed obUquely against the sides, 
the punch will punch the hole in the middle of the spring, as 
shown by the dotted lines at BA. This punch answers well, 
and the pHers can be used for putting in pins as usual without 
any inconvenience. A smaller punch in a pair of long-nosed 
follower pliers without the bridge is also useful. With these a 
hole can be punched in the inner coil of a spring for the barrel 
arbor without uncoiling the spring. The above punch can be 
also recommended on the score of cheapness, as the pliers cost 
only IS., and the old-fashioned punch to screw in the vice costs 
IS. 9d., and the clumsy Swiss mainspring nippers cost 6s. 6d. 

• Geneva Oylinders. — The length of a cylinder can be 
obtained by, the following method : — Take off both jewel 
covers, screw on the cock, and take the distance outside the 
jewel holes with a pair of pinion gauges — this is the entire 
length, pivots and all. The diameter is obtained from the 
scape-wheel thus : If the foot of the cylinder is held between 
two teeth and against the point of one, the heel of the next 
must be quite free of the cylinder. With a depthing tool, the 
watchmaker can put the scape-wheel and cylinder into it, and 
see if the cylinder has the same freedom inside and outside, 
that is, the tooth should have equal " drop" into the inside and 
on to the outside of the cylinder ; but the point of the tooth 
should not drop too far into the cylinder — just enough to be 
safe is all that is required. There are three dots, one on the 
plate close to the edge of the balance, and another on the rim 
of the balance to mark the place for the hair-spring stud, and 
when the balance is at rest, the dot on it is close to the middle 
one on the plate. In new watches these dots mark the extent 
of the balance and of impulse, that is, a tooth escapes when 
the dot on the balance reaches the outside dots on the plate. 
Before the balance is riveted too tight the cylinder should be 
put in and tried, and the balance turned round on the cyhnder 
until the teeth escape at the dots ; you will thus get the bank- 
ing, and also the escapement, right at once. 

Silver Dial Cleaning, — Take about a teaspoonful of salt- 
petre, and mix it with about two dessert-spoonfuls of finely- 
powdered charcoal — willow coal is the best. Let these be 
ground together with a little water on a piece of slate, with the 



HOROLOGY, 169 



blade of a knife, then, by the aid of a cameFs-hair pencil, 
spread a portion of the mixture evenly over the surface of the 
dial, which must then be laid on a piece of charcoal, and with 
a blow-pipe, and the clear flame of a lamp or gas jet, it must 
be made just red hot, and kept so till the wet powder has 
ceased to fly about ; it must be then thrown from the charcoal, 
hot as it is, into a mixture of sulphuric acid and water (in the 
proportion of about one fluid ounce of acid to three half-pints 
of water) ; it will then have a snow-white appearance, and must 
be washed with a brjish and soap in clean soft water, and put 
into fine sawdust till quite dry, or, what is better, rosewood 
raspings. 

To Make a Chronometer Oven. — A box suitable for testing 
watches with compensation balances, or even the effect of high 
temperatures upon aneroids, may be very efficiently constructed 
as follows : — 

Make an outer box, either of mahogany or oak, and line it 
with sheet-iron or block tin ; let it have an aperture in front large 
enough to admit of lighting the gas jets, which must be placed 
in the apparatus to obtain the required internal heat, the pipe 
for which should lie at the bottom of the box bent in the form 
of a circle. At about four inches from the bottom a diaphragm 
of perforated sheet-iron should be fitted. It need not be made 
a fixture, but should be supported by brackets at the corners. 
This diaphragm will receive the principal heat from the jets, 
and tend to distribute it more equally. In the interior space 
a sheet-iron trough, with overlapping edges, should be placed 
so as to rest upon the rim of the outer box. Its dimensions 
should be such as to allow a space of two or three inches in 
clearance at the sides and bottom between it, the outer box, 
and the diaphragm. Lastly, a light lattice-work cradle, made 
of wood, should be placed inside the inner iron box, for the 
purpose of holding the chronometers, watches, or aneroids to 
be tested. The lid to the whole apparatus should have a panel 
of plate-glass through which the contents of the cradle will be 
visible always. The lid should fit closely at the edges, so as 
to retain the heated air in the cradle. Apertures must, of 
course, be provided at the upper portion of the outer box to 
permit the products of combustion to escape. These apertures 
should be provided with sliding shutters or covers, to admit of 



I70 



HOROLOGY. 



them being entirely or partially opened so as to regulate the 
draught, and thereby the temperature of the interior. The 
dimensions of the various parts are not given, as the size of 
the box must depend upon the various requirements of different 
individuals. 



Gauge for Measuring Watch-Hands.— The following en- 
graving and description of a gauge for measuring watch-hands 
is forwarded by Mr David Meek of Edinburgh : — 

The gauge stands upon three pillars \ in. long, and consists 
of a disc of brass 2^ in. in diameter. In the centre of this disc 
is a steel-pumping centre, while around it are engraved 21 

circles. These 
circles are to show 
the lengths of the 
hands, and are 
sufficiently varied 
for hour and mi- 
nute hands of 
every kind. On 
the outside of the 
2 1 St circle are 
placed 40 Steel 
Studs about 3-16 
of an inch long, 
and slightly taper- 
ing, and of differ- 
ent sizes. No. I 



being the smallest, 

and 40 the largest. 

The object of these 

studs is to gauge 

the size of the hour-hand sockets, and like the circles for the 

lengths are so varied that they embrace every size of socket 

from the smallest Geneva up to the largest English one. 

As few watchmakers would feel inchned to purchase a hand- 
gauge, owing to its expense, the inventor has, to remove this 
difficulty, engraved a steel-plate with circles on it, correspond- 
ing in size and number to those upon the real gauge, and with 
small rings, corresponding exactly in size with the steel-studs, 
by which the hour sockets are sized. From this plate cards 




HOROLOGY, 



171 



have been printed, which serve nearly as well as a real gauge, 
without its expense. 

To ascertain the length of a hand by this gauge-card, place 
the socket or square exactly over the small dot in the centre, 
and see which circle the point reaches to. To obtain an hour- 
hand with a particular size of socket, take the size of the hour- 
wheel socket with a pinion-gauge or spring callipers, and then 
see with the callipers what ring corresponds in size. The 
white space within the rings denote the size of hole in the 
hour-hand. 

As there are at least 400 different sizes of hands in general 
use amongst the various kinds of watches, the watchmaker 
cannot fail to see the value of a gauge which enables him to 
obtain any size of 
hand he is in want 
of, or those sizes 
most suitable for 
his trade, besides 
its other advan- 
tages, such as the 
saving of time, 
surplus stock, &c. 

Another ar- 
rangement which 
renders the gauge- 
card still more effi- 
cient is by placing 
the watch - hands 

on a gauge similar to the second one. The gauge has the size 
of sockets as well as length of hand marked opposite each. As 
the spaces get empty, they can again be replaced by merely 
referring to the numbers marked within the empty spaces, the 
hands being fixed on the card so as they can be taken off and 
again replaced with little trouble. 

Watch Oil, to Purify. — Fill a phial three parts with olive 
oil, and hang it up in a window for six months, where it is 
exposed to every change in the weather. The impurities will 
then be precipitated. 

Horizontal Sun-Dial. — This sun-dial does not require the 
assistance in making it of a dialling scale — an instrument not 



LENCTH or 

MINUTE HA(V» 








=: 


= 


— 


= 


— 


= 


__ 


^ 






il7 


.•= 


== 


LENCTH ff r 
HOUR HANItS 




a 

r 


= 


<> 






















^ 


SIZE OF 
sack ET5 


i 


\ 





5 


6 


5 























6 

























172 



HOROLOGY. 



always to be readily obtained. On the centre E describe a 
circle. Through E draw the Hne DE, also HL, for the 12 line, 
at right angles to DE. Choose a point, say L, on the Hne HL, 

below E ; through 

L draw a line par- 
allel to DE. Draw 
from L a line LB, 
making with the 
line LH an angle 
equal to the height 
of the pole, or lati- 
tude of the place. 
^^t one leg of your 
compasses at E, 
and take the near- 
est distance to the 
line LB, which will 
be found at K. Then turn your compasses, and mark the 
point H on the line LH ; through H draw a line GH parallel 

to DE. From H, 




^ ^ ^ "^ ^ with the distance 

HE, draw the arc 
HEG. Divide this 
arc into six equal 
parts; then from H 
draw lines through 
the points of divi- 
sion in the arc to 
the line DE ; then 
from the point L 
draw lines for the 
hours> through the 
line DE, at the 
points where the 
lines which divide 
the arc meet the 
line DE. 

Another fnethod, 
— Proceed as di- 
rected below, and you will obtain an accurate dial. Draw the 
lines AB and CD at right angles to each other, and at the 




NORTH 



HOROLOGY. 



173 



intersection of which as a centre, describe the concentric circles, 
the size of the dial required. The Hne AB is the six o'clock line, 
and the line CD the meridian or twelve o'clock line. To fill 
up the intermediate hour lines, 7, 8, 9, 10, and 11 in the quar- 
ter CB should be measured by degrees from the meridian line ; 
that is, from 1 2 to 11 the distance should be 1 1 degrees and 
55 minutes ; from 12 to 10, 24 degrees and 26 minutes ; from 
12 to 9, 28 degrees and 13 minutes ; from 12 to 8, 53 degrees 
and 44 minutes ; 
and from 12 to 7, 
71 degrees and 9 
minutes. The quar- 
ter AC must be the 
same, andthehours 
4, 5, 7, and^ 8, on 
the south side of 
the six o'clock line, 
should be diame- 
trically opposite the 
same hours on the 
north side. The. 
gnomon, as shown 
in dotted lines, 
should be an angle 
of 52 degrees, and 
raised directly over 
the meridian, or 
twelve o'clock line. 

Inexpensive 
Sun - Dial. — The 

sketch shows the 
upper part of a 
cubical stone, hol- 
lowed out on three 
sides, and set up 
in a slanting posi- 
tion. The hollows 
form half a circle. 
The western side cannot be shown in the sketch, but it is the 
same as the east with the figures reversed. The dark angles 




174 



HOROLOGY, 



of the sketch throw the shadow on the hollow part, 
in the usual manner. 



It is set 



Pinion and Rack. 

— To strike out a 
pinion and rack, 
proceed as follows : 
We presume you 
have your diame- 
ter of pitch - line 
A. Divide it out 
for the teeth at A, 
and strike them 
out as shown at 
B^ and C^ The 
B^ in both are 
struck from a drop- 
line D, as shown 
by the dotted lines, 
and C^ are struck 
from the pitch-line 
alone. There are 
many variations, ac- 
cording to strength, the kind of work, and different speeds. 




liiiiiiiii iiiiiii ■ Jiiiiii^-iiii lil- Jill' illil-J 




same as if we measure from B to E. 



Diameter of Circle. 

— To get at the 
diameter of the pitch- 
circle, let AC and 
DF be the top and 
bottom of the teeth 
of a wheel, then B 
and E will represent 
the pitch-circle. It 
will be clear that if 
we measure the dia- 
meter of C, the bottom 
of the teeth on one 
side, to F, the top of 
the teeth on the other 
side, it will be the 



GLASS. 



175 



Epicycloidal Wheel. — A method of converting circular 
into alternate motion, or alternate into circular, is shown in 
the accompanying sketch. A is a fixed internal-toothed annular 
wheel ; the pinion B 
is attached upon a 
crank arm CE, which 
has its centre of mo- 
tion at E, and carries 
the centre C ; the rod 
D being attached to 
the pinion B (which 
is half the size of the 
annular wheel) at F, 
the circumference of 
revolution of the D 
pinion is thereby made 
to describe the right 
line DG, coinciding 
with a diameter of 
the annular wheel, 
which is therefore 
equal to the length 
of the stroke of the 
engine to which it 
may be applied. This 
arrangement admits, 
in small engines, of 




a very elegant application known as 



White's parallel motion. 



Glass, to Cut without a Diamond. — This operation unites 
utility with amusement. Take a bit of walnut-tree, cut one 
end to a point, put that end into the fire till it is red hot ; while 
the stick is burning, draw on the glass with ink the form you 
mean to cut ; then take a file, or a bit of glass, and scratch 
the place you intend to begin your section ; then take the wood 
red hot from the fire, and lay the point of it about the i-2oth 
part of an inch from the marked place, taking care to blow 
always on that point, in order to keep it red ; tallow the draw- 
ing traced on the glass, leaving the same interval as before. 
The pieces, with slight pressure, will then divide. 

Another method, — Tak^ any vessel you want cut, and, having 



176 



GLASS. 



of glass. 



heated a poker in the fire till it is almost red hot, but not quite, 
apply it to the part you wish the crack to begin. Having held 
it to the part for about a minute, remove the poker, and wet 
the place ; the glass will immediately crack. Having now 
begun the crack, you may lead it in any direction by merely 
drawing the hot poker in the direction you want. This is ex- 
tremely useful in many chemical experiments, where you are in 
want of proper apparatus. Glass tubes may be cut with a file. 

To Cut Circular Pieces of Glass. — If the amateur has a 
turn-table on which he mounts his objects, and a writing 
diamond, he has all that is required to cut the circular pieces 
It is only necessary to fix the square pieces of glass 

on the centre of the 
table, and hold the 
diamond with the 
right hand while he 
turns the table with 
the left. 

The following 
diagram will illus- 
trate all that is re- 
quired : — A is the 
stand for table; T, 
table; P, pole fixed 
into stand of table; 
C, arm to hold the 
diamond; K,K, K, 
keys to tighten the 
aim C and the dia- 
mond D ; G, the 
square piece of glass fixed to table by the two pieces of brass 
B, B, which each have two holes, so as to tighten the piece of 
glass G. The pieces of brass are fixed by two screws, as can 
be seen. These two pieces of brass will do to hold the slide 
on the table when required for mounting objects. 

To Cut a Circular Hole in a Sheet of Glass. — Drill a 
number of small holes close together to form a circle as large 
as the hole is required to be, then join the holes with a small 
file. The drill must be quite hard, and both drill and file 
wetted with spirits of turpentine and oil of lavender. 




JlLl. 



Eu< 



7? 



L_T 



HKT 



W 



GLASS, 177 

Designs on Glass. — A mode of effecting this, which is a 
modification of the process by which copperplate engravings 
on paper are transferred to porcelain, has been invented in 
France. As fine-lined copperplate engravings would not adhere 
to glass, others having considerable depths are used ; also, to 
impart to the enamels that thickness which the glass requires, 
stearates and oleates are added to the silicates and borosilicates, 
which serve to support or to fuse the coloured and colouring 
oxides ; and, for a vehicle, a solution of resin in ether or ben- 
zine is added to the mixture. Impressions, taken mechanically 
on paper with this ink from engraved rollers, are transferred 
to the glass, which is then treated as in similar processes with 
porcelain, and is finally placed in the furnace. Effects of great 
artistic merit are thus obtained at a trifling cost» 

To Transfer Engravings on Glass. — Metallic colours pre- 
pared and mixed with fat oil are applied to the stamp on the 
engraved brass or copper. Wipe with the hand in the manner 
of the printers of coloured plates ; take a proof on a sheet of 
silver paper, which is immediately transferred on the tablet of 
the glass destined to be painted, being careful to turn the 
coloured side against the glass. It adheres to it, and so soon 
as the copy is quite dry, take off the superfluous paper by 
washing it with a sponge ; there will remain only the colour 
transferred to the glass, which will remain fixed by passing the 
glass through the ovens. The basis of all the colour employed 
in painting on glass are oxidated metallic substances. In 
painting on glass it is necessary that the matter should be very 
transparent. 

To Draw on Glass. — Grind lampblack with gum- water, 
and some common salt. Draw the design with a pen or hair- 
pencil. 

To Paint Glass Gold Colour. — Take silver i oz., antimony 
\ oz. Mix them in a crucible, then pound the mass to powder, 
and grind it on a copper plate ; add to it yellow ochre or 
brickdust, calcined again, 15 oz., and grind them well together 
with water. 

To Paint Glass Eed. — Take jet 4 oz., litharge of silver 
2 oz., red chalk i oz., powder them fine, and mix them. 

M 



1 78 GLASS, 



Materials for Opaque Enamels. — Calcine 30 parts of 
lead with 33 of tin, with the usual precautions; then take of 
this calcined mixed oxide 50 lbs., and as much of powdered 
flints (prepared by being thrown into water when red hot, and 
then ground to powder), and 8 oz. of salt of tartar ; melt 
the mixture in a strong fire kept up for ten hours, after which 
reduce the mass to powder, 

Micagraphy. — This is the name , given to a new process of 
producing ornamental effects on sheets of mica. The use made 
of this new process has been as yet confined to the ornamen- 
tation of lamps and shop-windows, but it may be used as a 
cheap substitute for stained glass. The sheets of mica can be 
painted in any required manner, and the work preserved, it is 
said, by means of a varnish, or the painting may be fixed like 
enamel on the mica by the use of different pigments and the 
aid of a furnace, the pieces of painted mica being afterwards 
fixed, with the coloured side within, on the glass of the windows. 
This is the mode of proceeding : — After the mica is split into 
laminae and trimmed into shape, it is glued down upon card- 
board to be pohshed and printed. The former operation is 
performed by means of a soft rubber moistened with a solution 
of soap or sulphuric acid extremely diluted with gum-water : 
the printing is performed in the ordinary manner or by transfer, 
in order to present the design in the natural position so as to 
be seen by transparency. Opaqueness is produced by a pre- 
vious coat of varnish or a metallic ground obtained by means 
of leaf or powder. The colours are laid on as in illuminated 
works, and the ordinary pigments may be employed, and after- 
wards covered with a transparent spirit varnish, or, as before 
stated, enamel colours may be used and the sheets passed 
through the fire. It is admitted, however, that in the latter 
case one great advantage of the process, namely, cheapness, is 
in a great measure sacrificed. When the ornamentation is 
completed, the mica is removed from the card and fixed on 
glass, or any other substance, by means of a solution of gum 
sandarac and mastic in potash and alcohol. It is said that, 
with ordinary care, the junction of the pieces of mica in a 
mosaic or other work is quite imperceptible, so that, in the case 
of a painted window, there is no other limit but the size of the 
glass on which the mica is fixed. 



WOOD' WORKING. 



179 



Soluble Glass. — A covering for decayed wood and other 
practical purposes. Fifteen parts of powdered quartz, 10 of 
potash, and i of charcoal. These are melted together, worked 
in cold water, and then boiled with 5 parts of water, in which 
they entirely dissolve. It is then applied to wood-work, or any 
other required substances. As it cools it gelatinizes, and dries 
up into a transparent colourless glass on any surface to which 
it has been applied. It renders wood nearly incombustible. 

Woods, Strength of. — The strength of different woods to 
resist a compressive strain depends upon the value of the 
absolute force or weight which has been found by experiment 
to crush them, and which has a very wide range. The annexed 
table shows the crushing weight for all the woods which are 
used in the various branches of constructive art, and from 
these numbers and simple rules it will be easy to calculate the 
strength of pillars of different lengths and sizes. 



Description of Timber. 



Alder 

Ash 

Birch 

Beach 

Box 

Elm 

Ebony 

Hornbeam 

Larch 

Mahogany , 
Oak 

Pine (Red) 

Pine 

Sycamore . 

Spruce 

Teak 

Watergum 



Crushing 

Weight in 

cwts. per 

square inch. 



61-50 
80 
104 

92 
92 

170 

65 
50 • 

73 
89-25 

53'5o 
68-75 

5175 
48 

63-25 
61 
108 
90 



Safe Load 

in cwts. 

per square 

inch. 



15-40 

20 

26 

21 

23 

23 

42-25 

16-25 

12 50 

18-25 

22.25 

13-40 

17-20 

13 

12 

15-80 

15-25 
27 
22' 50 



Timber, where 
Grown. 



England. 
America. 



West Indies. 

America. 

England. 

Honduras. 

England. 

Canada. 

Dantzig. 

America. 

The Baltic. 

England. 

America. 

Africa. 

East Indies. 



Warped Wood. — The best method of straightening warped 
wood is to wet it. well on the hollow side, and clamp a piece of 
hot wood top and bottom with hand-screws, such as cabinet- 



i8o 



JVOOJD' WORKING. 



makers use, until cold ; then, if convenient, screw a piece of 
hard wood on the under side, and let it remain on. Another 
plan is to cut down the middle, shoot the edges, glue together 
again, and plane flat. 



Dovetailing. — In plate i several ways of working are 
shown, but as much depends upon the parts being properly- 
proportioned which are to fit into each other, so that the pin 
or socket, partly represented in fig. i, called the pin of the 
dovetail, and that in fig. 2, called the socket, shall be as nearly 
as possible of equal strength, we lay down some rules for the 
guidance of the workman, and here refer to the pin only in fig. 
I, for the socket is made to correspond to it. Let ABCD be 
a scantling required to be joined to another by means of a 
single dovetail. Now as much will depend on the form of the 
dovetail as the proportion it bears to the parts cut away, we 
will endeavour to lay down the principle on which the greatest 
strength is maintained. Having squared the ends of the 
scantling, and gauged it to the required thickness AIKLM, 

divide IM into three 
equal parts at KL. 
Let KL be the small 
end of the dovetail, 
and make the angles 
IKG and MLH 
equal about 75 or 
80 degrees. Now 
make GE and FH 
parallel to AN and BO. Here introduce the saw, and cut 
away the pieces AIKGEN, and BMLH FO ; and having cut 
fig. 2 to correspond by making the form of the dovetail on the 
top of the piece ABCD, it will fit together, as shown in fig. 3. 

According to the texture of the wood, we may make the 
bevel of the dovetail or angle IKG, fig. i, either more or less. 
Hard, close-grained wood, not apt to rive or split, will admit of 
a greater bevel than that which is soft or subject to chip: thus 
the dovetail in deal must be beveled less than that in hard 
oak. It is a fault in many workmen that they give the dove- 
tails too much bevel, which, instead of holding the joint firmly 
together, weakens it. This may be observed if we compare 
the dovetailing of the cabinetmaker and the joiner ; the former 




J^ 


7~ 


.(^ 


< 




WOOD- WORKING. 



i8i 



has very little bevel, while the latter has very much. Even 
with respect to the appearance of the work, the one looks neat, 
and is at the same time strong ; while the other, appearing to 
aim at great strength, looks clumsy, and is in reality the 
weaker. Fig. 4 represents the dovetail in common use for 
drawer fronts, &c., when it is wished to hide the appearance of 
the joint in front. The board ABCD is cut with the pin, and 
AEFB with the socket ; the pins in this sort of dovetail are in 
general placed one 

inch apart. Fig. 5 '^ ^ - ^ 

represents the pin 
part of tap dove- 
tail, which when 
put together shows 
only a joint, as if 
the pieces were 
riveted together, as shown in fig. 6 
sents the pin, and the part EFGH 
when put together only shows the line HG as a joint ; and if 
the corner AB is rounded to the joint GHT, it will appear as 
if only mitred together. This kind of dovetail is very useful 
for many purposes where neatness is required. Fig. 7 is a still 
neater dovetail. Instead of the square shoulder or rebate in 
AB, it is cut into 
a mitre, and the 
other piece is made 
to correspond. An- 
other very neat way 




the 



, ...^ part ABCD repre- 
the socket dovetail, and 




ft 



is shown in fig. 8, 

where the joints are 

first formed into a 

simple mitre, and 

then keyed together 

either by making a 

saw kerf in a slanting direction, as shown at AB, or by cutting 

out a piece as at CD in the form of a dovetail, and fitting a 

slip in of the required form. The first method, as AB, is 

amongst workmen called keying together ; the second, as CD, 

is key dovetailing ; the last method is shown at fig. 9, and may 

be termed mitre dovetail grooving, the part AB being formed 

with shoulders cut to the required bevel, and a piece left for 



l82 



WOOD- WORKING. 




the pin dovetail, which is inserted into the socket dovetail, 
made to correspond to it in the piece CD, which has been 

previously formed 
fio I ^ into a mitre. This 

method, though not 
much employed, 
may be used with 
great advantage in 
many cases, parti- 
cularly when we 
wish to join any 
pieces together the 
lengthway of the 
grain. 

Annexed are three 
other illustrations 
of dovetailing, suf- 
ficiently shown in the engravings as to need no further 
description. 

Wood Staining. — To Stain Wood a Mahogany Colour 
before Polishing, — Make a strong or weak solution of logwood, 
according to shade required, to which add a few drops of 

hydrochloric acid ; 
then stain the ar- 
ticle. When dry, 
give a coat of lin- 
seed oil, and it is 
ready for polishing. 
If boiled or strong 
drying oil is used, a 
much darker shade 
is obtained ; with 
the latter it becomes 
almost black. 

Another tnethod, 
— Boil logwood 
chips in water, add- 
ing a little soda or potash to bring out the colour. Apply with 
a brush, and use French polish when dry. 

Rosewood Stain. — A stronger decoction of logwood must be 




WOOD- WORKING, 



183 




used, and the process must be repeated several times. To 
produce the fibres, put some iron-filings or turnings in strong 
vinegar ; let it stand for some years, and then brush the wood 
over with the solu- 
tion. When dry, 
polish with bees- 
wax and turpentine. 

Another method. 
— Dissolve half a 
pound of potash in 
2 gallons of water, 
and add to it half a 
pound of red san- 
der-wood. When 
all the colour is 
extracted from the 
wood, add 5 pounds 
of gum shellac, and 
dissolve it over a 

quick fire. This stain should be used on a grourtd previously 
with logwood stain. 

Another method. — If with a brush dipped in the brightening 
liquid you draw veins on wood prepared with the black stain, 
a very good effect is produced. 

Red Stain for Bedsteads and Common Chairs. — Lay on one 
or two coats of common archil, and when dry brush over with 
a hot solution of pearl-ash in water. 

To improve the Colour of Stains. — With 2 oz. of nitric acid 
diluted with 4 oz. of water, mix a teaspoonful of muriatic acid 
and \ oz. of grain tin. Keep in a bottle well corked, and use 
after it has stood two days. 

To Stain Beech a Mahogany Colour. — In a pint of rectified 
spirits of wine put an ounce of dragon's blood. Shake the 
bottle which contains it frequently until the dragon's blood is 
dissolved. When this is the case, the stain is ready for use. 

Black Stain for immediate use. — Take i lb. of logwood 
chips and boil in 4 quarts of water, and lay it on the work 
while hot. Make a similar decoction of logwood to the last, 
and add to it i oz. copperas and 2 oz. verdigris ; strain and 
put into it I lb. of rusty steel filings, and with this go over the 
work a second time. 



^84 HOUSE AND GARDEN. 

Protection of Wood Carvings. — Worm-eaten wood may 
be saved from further ravages by fumigating it with benzine, 
whereby the worm is destroyed. Another way is to saturate 
the wood with a strong solution of corrosive subhmate — a pro- 
cess which may be advantageously employed to protect carvings 
in wood. But as sublimate destroys its colour, it will be 
necessary to restore the latter by ammonia, and then by a very 
dilute solution of hydrochloric acid. The holes made by the 
worm may then be injected with gum and gelatine, and a var- 
nish of resin dissolved in spirits of wine should afterwards be 
applied to the surface. 

Shooting Boards for Joiners. — This plan brings the two 
edges of boards true for glueing together, and possesses evident 
advantages over those in general use. ^, bed of some hard 
wood ; bb^ table supported by blocks ccc ; d^ a block carefully 

planed and fitted 

^ 6 \^ at right angles to 

r itvi ' ' ifci ' gT^^ ^^^ table. With 

' ^ this board the whole 

of the plane-iron 
is brought into use, instead of one part only, as in the board 
usually adopted. Of course the plane-iron would have to be 
perfectly straight on its edge, otherwise it would bring the 
edges of the board false. 

Waterproof Mortar. — The admixture of coal-dust with 
mortar renders it impervious to water. This waterproof mortar 
may be made by mixing two parts of fine cement with one part 
coal-dust reduced to a very fine powder, and one and a half 
parts slacked lime ; then adding water, so as to produce the 
desired consistence. Mortar thus made possesses great soli- 
dity ; but the darkness of its colour is often an obstacle to its 
use. 

Damp on Walls. — A complete cure from damp exuding 
from a brick wall upon which no plaster, much less paper, 
would adhere, on account of its having been several times 
saturated with sea-water, has been effected by using '' Italian 
plaster." The cost is but little more than that of Portland 
cement, and may be papered upon forty-eight hours after being 
used, without any risk of damp or discolouration. 



HOUSE AND GARDEN. 



I8S 



Cleaning Paint. — -Dissolve 2 oz. of soda in a quart of hot 
water, which will make a ready and useful solution for cleaning 
old painted work preparatory to repainting. The mixture in 
the above proportions should be used when warm, and the 
wood- work be af- 



terwards washed 
with water to re- 
move the remains 
of the soda. 

Door -Spring. 

— The following 
is suggested as 
a simple spring 
for a door. It 
consists of half of 
a hook-and-eye 
hinge, fixed in 
two places on the 
door- stile, and in 
one place, near 
the top, on .the 
facing or archi- 
trave. A piece 
of wire, |- of an 
inch in diameter, 
passes from the 
lower eye straight 
through the cen- 
tral one, and is 
then bent out, so 
as to pass into 
the upper eye on 
the architrave. 
The action of 

opening the door strains the wire, and the spring acts by its 
reverting to its former position. 

Marble, Imitating. — How to make a stucco mantelpiece 
look like black marble. Make a mould of wood and line it with 
plate -glass ; and mix stucco with size, to keep it from setting 




1 86 HOUSE AND GARDEN. 

too fast. The colour ought to be put in among the stucco 
before mixing ; then spread a thin coat on the glass, rub it 
well to take out the air-bubbles, and fill the mould up with 
clean stucco before the first sets. After it has set, dip the 
mould in water, and it will come out easy. So soon as it is 
dry, dip it into size mixed with black, and then cover with 
black varnish. Do not touch it with the fingers after it has 
come out of the mould. Use mineral colours, and be certain 
that there is no oil in them. Any other kind of marble may, 
by a little ingenuity, be imitated when the first coat is laid on. 
A better kind of mould can be made by taking an original and 
covering it with clean glass, and then pouring wax, such as 
plasterers use, over the glass. 

Architectural Ornaments in Relief. — For making archi- 
tectural ornaments in relief, a moulding composition is formed 
of chalk, glue, and paper paste. Even statues have been made 
with it, the paper aiding the cohesion of the mass. 

To Take out Iron Stains. — Mix in a bottle equal quantities 
of fresh spirit of vitriol and lemon juice, wet the spots, and in 
a few minutes rub them off with a piece of soft linen. 

Anti-Pestilential Vinegar. — Take acetic acid (s"") 900 
grammes, camphor in powder 5 grammes, crystallised phenic 
acid 100 grammes. This combination of three antiputrescents 
is said to be extremely useful, and for hygienic purposes far 
superior to " vinegar of the four thieves,'^ as toilet vinegar was 
once called. It has been used on board ship to keep cabins 
sweet. 

Preparation of Walls in Tempera. — When it is wished 
to colour a wall, not retaining the plaster or stone as a ground, 
the following order must be observed. First mend any broken 
parts with a mixture of putty and plaster-of-Paris neatly put 
on with a spatula or palette knife, and smoothed down ; then 
brush over the walls with a size, composed of i lb. of good 
glue dissolved in i gallon of hot water, thickened with some 
red lead, or else with Young's patent size. Give this suf^cient 
time to dry. Now proceed to make your ground colour, which 
we will suppose to be what is usually called vellum tint, as 
follows : — In a large double-sized paint-pot put 3 lbs. of 



HOUSE AND GARDEN. 



187 



gilder's whiting, cover it with water, and let it be until it be 

perfectly broken up and saturated, and the effervescence has 

subsided. Then pour off the water, and stir with a thick stick 

until the mass has attained the consistency of dough. Melt 

Young's patent size not diluted, and pour upon the whiting, 

stirring well up, and then straining while warm to free from 

impurities. Let this stand several 

days in a cool place until it is formed 

into a weak trembling jelly, so as to 

be worked with ease with a stiff 

brush. Before the size is added it 

may be stained to any tint which is 

desired by the addition of the pro- 
per colour ground in water. It 

should be observed that all colours 

in distemper dry lighter than when 

first applied, so that the only way to 

secure the requisite tint is to make 

experiments upon a piece of paper or 

card until the proper tint is reached. 

The colour must then be applied 

to the walls in its cold and jellied 

state. For this purpose, use a large 
hog's-hair brush, and work with 
decision and freedom, taking care 
not to retouch any portion of the 
work, but to cover the ground well 
as you proceed. The wall should 
be divided by your eye into squares, 
advancing from one to another in 
regular succession, and, of course, 
beginning from above. Unless for 
some special purpose, your ground 
should never be pure white, but be stained, however little, with 
black, blue, ochre, or chrome yellow, to take off the raw appear- 
ance ; where a coloured ground is needed, proceed in the same 
way as above described, commencing with a larger or smaller 
quantity of whiting, and tempering it in the colour to the degree 
required. 




Chimney Cowls. — The above simple arrangement of cowls, 



HOUSE AND GARDEN. 



constructed on the principle of the air blowing through, draws 
up the smoke. They have been largely tried, and have per- 
fectly succeeded. 



Cowl for Smoky Chimneys. — Let O be a tube of any 
length, 9 in. diameter ; S also is a tube, and base to O, being 
14 X 9 in. ; N is a tube 16 x loi in., upon which is fixed 
another tube M, at XE ; M is a tube through which air passes 

to carry off the 
smoke. In M ab\s 
20 in., cd\'s> 17 in., ac 
is I o in. diameter, ex 
is 3 in., ed is 4 in. 
Visa funnel-shaped 
piece of iron, which 
is fixed at AC, being 
from the line AC to 
the opening K, 4^ 
in., ofwhichK, being 
a tube, is 2 in. long 
by i|^ in. diameter, 
which passes over 
the mouth of N, i J 
in.; BD is the out- 
let ; O is a rod of 
iron fixed at the top 
of O, upon which 
turns M at the point 
T. Z is a piece 
of sheet-iron fixed 
on M, from T to 
B, which turns M 
against the wind, 
bringing the cone V 
open to it, by which 




the wind, having to pass through it, carries off the smoke 
at BD. 



Stains on Marble, to Remove. — Various plans are adopted 
for taking iron and ink stains from marble — such as chimney- 
pieces and wash-hand stands, &c., but the following will be 



HOUSE AND GARDEN. 



189 



found most practical : — Mix unslacked lime in very fine powder 
with strong soap ley ; make it thick, and leave on the marble 
for more than a week. Then wash off with a thick lather 
of soft soap, boiled in soft water. Clear off the soap, and 
brush with a little Hme powder, and a fine polish will be the 
result. 



Closet Construction. — Dry earth is no doubt a great deo- 
doriser, and the principle has been adopted with considerable 
success. It answers under two conditions, that the earth 
should be thrown down perfectly dry, and kept dry ; but 
is it so ? How many receptacles are commonly emptied 
into the waste, or, if not, down some open sink ? We 
may suppose that in a town there will be a greater adapta- 
bihty of water than in the country, whilst in the latter there 
will probably be attached to the dwelling a strip of garden 




ground into which the manure may be deposited, as in the 
earth closets. The annexed sketch will illustrate the prin- 
ciple : — ^, closet pan ; ^, wall of house ; ^, a wooden water- 
spout for carrying down any spare water from the roof, or for 
letting gases pass away into the open air ; <:, water-tight tank 
with flag top, calculated to require emptying of solid contents 
once in three years ; ^, an 1 8-in. drain, running into a second 
tank ^, which holds the liquid manure at the bottom of the 
garden ; f^ a smaller waste-pipe of some length connected with 
a drain. The pan is a simply- made affair of sheet zinc 
painted, with a rim turned over at the top, and a bottom on 
hinge to balance about a quart of water or so. Over the rim 
comes a false seat, and all is air-tight. The rim is embedded 



190 



HOUSE AND GARDEN, 



in putty. After use a small quantity of water is poured down 
with a can ; but where water from the main can be pro- 



^^^ss^s 



SSSg 







5r= 



is not the slightest unpleasantness. 



cured, there would 
be no difficulty in 
adjusting a com- 
mon pipe to the 
side of the basin, 
with an ordinary 
tap inserted in the 
length of pipe with- 
in reach. With 
this principle there 



Ventilation. — A simple way of ventilating a roo7n that has 
a chimney in it is the following : — Make an opening in the 
chimney over the fireplace, and as near the ceiling as possible, 
about 9 in. by 2| in., then procure a piece of perforated zinc, 
10 in. by 3^ in., and a piece of oiled silk or calico 9 in. by 3 

in. ; fasten the silk 
or calico to one 
edge of the zinc by 
sewing it through 
the holes ; it will 
then hang loose on 
the zinc as on a 
hinge, but it will 
not reach the ends 
or bottom edge by 
half an inch ; now 
fix the zinc over the hole, with the flap inside, notjki the room, 
and with the edge that is secured uppermost. A strip of paper 
bordering may be posted on the wall, and partly on the place, 
to hold it. The up-draft will blow the silfe back, but the down- 
draft of the chimney will close it. 

Cheap and Effective Filter. — Procure one small, low, but 
broad tree-pot, and two very large ones, both of a size ; also a 
large deep water-pot or tub, and a supply-cask or tub ; then 
get five or six feet of gutta-percha piping, and two small pieces 
of the best and finest sponge, and close up the holes in the 




HOUSE AND GARDEN, 



191 



large tree-pots tightly with the sponges. Place one of the tree- 
pots within the other, so that the sponges do not touch each 
other ; this being done, and all in readiness prepared, the 
sand, pounded glass, or charcoal being thoroughly washed 
clean from dirt or dust, first put the small tree-pot into the 
water-pot (it being previously raised upon some bricks), and 
fill up the space between the sides of each, to the tree-pot 
brim, with sand, pounded glass, or charcoal broken small. 
Now put the two large tree-pots together into the water-pot 
also, to rest upon the small tree-pot, and again fill up with 
sand between the outer tree-pot and the water-pot ; then pour 
water on the sand all round, so that it may find its bed or level, 
and repeat the sand and water until the level of the sand be 
near the top of the water-pot. You may now put one end of 
the tube or pipe through a hole made in the upper part of the 
supply-cask, so as 
to nearly reach the 
bottom ; then draw 
up the water into 
the pipe with the 
mouth, keeping the 
end depressed, and 
the syphon will be 
in action, placing 
the other end in the 
water-pot. Your fil- 
ter being now made, 

you will soon obtain clear water from the upper tree-pot, which 
you can lead out or draw off, which is preferable, with another 
short syphon, into a receiver. 

Having once had need of a filter we adopted a similar plan, 
with charcoal between the two large tree-pots, with a piece of 
flannel surrounding the sides and bottom of the upper tree-pot, 
minus the small pot and sand ; but in time the flannel is apt 
to rot and become unwholesome. 

C, the supply-cask ; SS, the supply-syphon ; Z, the stool of 
elevation for syphon action ; A, the water-pot ; UV, the large 
tree-pots; FW, filtered water; W, water ; SS, sand; R, re- 
ceiver of filtered water ; DS, discharge syphon ; LLL, lids and 
sponges ; KK, bricks ; N, notch made 




U, upper tree-pot ; V, the lower one. 



in tree-pot for pipe ; 
As the filtered water has 



192 



HOUSE AND GARDEN. 



to ascend, the action of this filter is preferable to those wherein 
it has to descend. 

Hat and Cloak Peg Frames. — Here is a portable hat and 
cloak peg frame, made either of mahogany or deal, framed 
together, about 3 feet long by 6 in. wide ; the framing is i in. 
wide, by | in. thick ; the pegs or hooks, hinged between on wire 

pins, are of the same 

Q . .0 

— »■ . * . — f- r ^ . fc ■ r — . 1 ., I 



u 



m^mz 



h^ 



thickness 
ing ; the 



as fram- 

letters A 

show the rails of 

framing, and it is 

hung with two rings 

as shown. It is suitable for either halls, backs of doors, or 

tents, and can be removed at pleasure. It can be made of any 

length, and the hooks fold flat as shown. 

Alarums. — From among the many ingenious contrivances 




known as " Early Risers' Friends, 
we select the above : — 

I. A is the kitchen, B the bedroom, and C the clock 



^ Mechanics' Friends,'* &c.. 

It 



HOUSE AND GARDEN, 



193 



does not matter if your clock has only one weight ; when the 
clock is in action, watch it for one hour ; notice how much the 
weight lowers in that time ; then divide it into a scale of halves 
and quarters ; after which, mark on the wall the hours, as 
shown at D. When going to bed, consider how many hours 
you wish to sleep. Example : Supposing it to be half-past 
ten, and you wish to rise at five o'clock, raise the weight E to 
half-past six. At five o'clock in the morning the weight E will 
press on lever F, down drops weight G, pulling string HHH, 
and down drops a heavy parcel on the legs of the sleeper. At 
the same time that weight I is lowering, round goes the cog- 
wheel K, pressing against the tin-spring L, which makes a 
great noise. Where there may chance to be a cupboard, as at 
MM, the string can go into it out of sight. NN is a short 
piece of elastic placed to keep the string on pulleys, when the 
weight G is Suspended at i, 2, 3, 4, 5, 6, 7, 8. Use round 
nails for wires to work on. No. 9 screw to slack or press the 
tin on wheel, 00 nails to secure alarum to wall, P balance- 
weight for I, and to keep string on pulley Q. In addition to 
the above, turn the 
light nearly out of 
the lamp at night, 
so that weight (I) 
can put full light on 
in the morning by 
lowering lever T. 

2. A, lamp ; 

B, spring holding 
socket for match ; 

C, centre tumbler, 
connecting the 
spring to the match 
holder; D, lever; 
E, pinion holding 
the spring, having 
a rough surface for 
the purpose of ig- 
niting the match ; F, whistle ; G, coffee can. 

3. The following is an apparatus attached to an ordinary 
alarum clock. It has been practically tried, and found satis- 
factory. It is enclosed in a frame or case, and suspended 

N 




194 



HOUSE AND GARDEN. 



against a wall, just below the ceiling, so as to give the weight 
plenty of room to run down. AB, arbor, bearing a fly-wheel 
C, in which are inserted, in a radial direction, two hammers 
DE ; these impinge on the inner edge of a gong F, suspended 




by a rod G. Round the arbor is rolled the cord H, which is 
acted upon by the weight I. This weight is suspended in the 
bight of a cord N, and is released on the running down of the 
alarum- weight J, as will be seen by the engraving. 

Water -Tight Cisterns. 

— Construct your cistern in 
the usual mode — viz., the 
sides nailed to the ends. It 
can scarcely be made tight 
by any paint or cement 
where the grain of the wood 
of end and side, or end and bottom, of the tank have a differ- 




HOUSE AND GARDEN, 



195 



ent direction, and are fixed together with nails. The pieces so 
joined are constantly sliding one on the other, the one swelling 
and contracting, and the other not — in fact, they cannot agree. 
The following arrangement will obviate this : — Secure sides to 
bottom, which should both have the grain of wood in direction 
of the arrow. Fit the end (the edges of which should be like 
those of a cask-head) into groove G, and nail the bottom 
of tank only to the lower edge of the end-pieces, the end-piece 
to have the grain up and down. The ends of sides to be drawn 
together by two or more screw bolts and nuts SS. Thus 
formed, when the sides swell, they have liberty by sliding on 
the edge of ends to expand or contract. If a tank thus made 
leak, let some pitch be melted into the seams with a heated 
ploughshare, or any convenient piece of iron, the wood being 
first thoroughly dry. 

Improved Way of Storing Rain-Water. — When casks are 
used to catch rain-water, holes are often cut in the higher ones 
to let the water fall 
into the lower. A 
better way would be 
to take a piece of 
gas - pipe, bend it 
into the shape of 
the letter U, and 
fill it with water, 
to exclude the air. 
Put one end into 
each tub, the one 
being full, the other 
empty. They will 
soon come to a 
level. In this way 
a number of vessels 
may be set all upon 
the level, without 
cutting or boring 
holes. 




Garden Engine.— BCEFH 
an air-vessel : BB is a barrel 



is a force-pump together with 
about 2 in. diameter by 10 in. 



long, made of copper or brass (a piece of telescope tube would 



196 



HOUSE AND GARDEN. 



answer very well) screwed into the stand (iron) CDEF ; H is 
an air-vessel ; I and J are the suction and delivery valves ; F 
is the deliveiy-pipe, to which should be attached a piece of 
indiarubber hose about |ths of an inch in diameter, at the end 
of which is a jet or nose. The piston is formed of two leather 

cups, the top one in- 
verted, which are 
held in their proper 
position by two col- 
lars to the rod. Dirt, 
&c., is prevented 
from entering the 
pump by means of a 
piece of iron gauze 
represented by dots 
beneath the nose DE. 
As soon as the handle 
is raised, the water 
enters the pump 
through the valve J, 
which closes when 
the lever is depres- 
sed. The water is 
then forced into the 
air - vessel through 
the valve I, which 
prevents its return. 
The air in H again 
being compressed, as 
soon as the power is 
removed, forces the 
water very rapidly 
through the delivery- 
pipe, &c. Should 
the pail AAAA not 
be required, the foot 




of stand must be larger, a piece of hose being attached to DE, 
and a stuffing-box placed at the top of the pump, to prevent the 
escape of any water that might pass the plunger. 



Double- Action Pump for Garden Engine. — By the sketch 



DRA WING AND MODELLING. 



197 



\iv 



i 



below, it will be seen that the water is kept constantly in a 
stream both with the ascent and descent of the piston. The 
sketch is so simple as to require 
no further explanation. 



Transfer* Paper. — Transfer 
paper may be prepared thus : — 
Make a mucilage with J'oz. of 
gum tragacanth; strain; add i 
oz. of glue and \ oz. of gam- 
boge. Mix French chalk 4 02., 
old Paris plaster \ oz., starch 
I oz. ; run them through a 
sieve, grind with the mixed 
mucilage, add water to reduce 
to the consistence of oil, and 
apply it with a brush to thin- 
sized paper. The drawing made 
on this prepared side of the 
paper is wetted at the back and 



I 

n 



placed on the stone, which is warmed to 125° Fahr. ; the whole 
is then strongly pressed in the lithographic press, and the stone 
receives the impression, which may be printed from as usual. 
When two impressions are required, a red composition is made 
of wax 2 parts, soap i part, and vermillion to colour, all melted 
in a saucepan, and ground with water to the consistence of 
cream. This is spread thinly on the second stone, an impres- 
sion from the first stone is next applied, and the second draw- 
ing is thus made to correspond .with the first exactly. If in 
printing the drawing becomes smutty, mix equal parts of water, 
olive oil, and oil of turpentine ; shake till they froth, wet the 
stone, throw this froth on it, and rub it with a soft sponge. 
The printing ink will be dissolved, and the drawing will almost 
disappear ; but, on rolling it, it reappears as clear as at first. 
When the stone is laid by for future use, a preserving ink is 
applied, to prevent the surface printing ink becoming too hard. 
Thick varnish of linseed oil 2 parts, tallow 4 parts, wax and 
Venice turpentine, of each i part ; melt ; add by degrees lamp- 
black 4 parts, mix thoroughly, and preserve in a tin case. This 
must be rolled on the stone each time before laying it aside for 
future use. When the whole of the impressions are completed, 



198 DRAWING AND MODELLING. 

and the stones required for other drawings, two of the stones 
are laid face to face, and ground with sand and water until the 
surfaces are clear. They are, finally, more or less polished 
with pumicestone, according to the required fineness, and are 
then prepared to receive other drawings. 

Tracing- Paper. — Having prepared a mixture of equal parts 
of turpentine and gum-mastic, spread out a number of sheets 
of crown tissue-paper, one over the other ; then brush the top 
sheet over with the above mixture, and hang it up to dry. 
Proceed with the rest in same manner. As the under sheets 
absorb some of the varnish laid on those above them, less will 
be used than if each was brushed separately. This varnish for 
tracing-paper leaves the paper quite light and transparent. It 
may readily be written on, and drawings traced with a pen are 
permanently visible. It is used by learners to draw outlines. 
The paper is placed on the drawing, which is clearly seen^ and 
an outline is made, taking care to hold the tracing-paper steady. 
In this way elaborate drawings are easily copied. 

Oiling Tissue-Paper. — Lay it on a flat surface, and rub 
linseed oil over it with a piece of cotton wool or a brush, and 
hang it up to dry. 

Stencil-Plates. — For cutting stencil-plates use a mixture 
of 3 parts nitric acid and i part water. After heating the 
plate slightly, prepare the ground for etching by rubbing it over 
with common heel-ball. The back of the plate should be oiled, 
so that the cutting may be clean. 

Drawing-Board, to Black. — Take \ lb. of lampblack, and 
put it on a fire-shovel over a clear fire until it is red hot ; then 
take it off, and, when cool, pound it very fine, and mix it with 
a pint of turpentine. This should be laid on with a size-brush. 
If the board is new, before using the above it will be necessary 
to give it one or two coats of lampblack mixed with boiled oil. 

Map Colouring. — Ordinary water-colour paints may be 
used, preferring the moist variety, and those not opaque, such 
as gamboge, carmine, indigo, or Prussian blue. With these 
all the colours required may be formed. Wet the sheets with 
clean water first, and as soon as the moisture has disappeared 
from the surface, apply a thin wash of the colour with a toler- 
ably full brush, passing over the surface quickly. Commence 



DRAWING AND MODELLING, 199 

at the top and at his left hand, coming down to the bottom 
right hand. Use blotting-paper to dry any superabundance of 
colour. 

Pencil Drawings, to Preserve. — Apply a thin wash of 
isinglass, which will prevent rubbing off either of black lead, or 
of hard black chalk. 

Pencil Writing, Indelible. — Some years ago the Society of 
Arts offered a premium for an indelible pencil to write on com- 
mon paper, but nothing satisfactory was produced. Any pencil 
writing or drawing may, however, be rendered as indelible as 
if performed with ink by the following simple process : — Lay 
the writing or drawing in a shallow dish, and pour skimmed 
milk upon it. Any spots not wet at first may have the milk 
placed over them lightly with a feather. When the paper is 
all wet over with the milk, take it up and let the milk drain 
off, and whip off with the feather the drops which collect on 
the lower edge. Dry carefully, and it will be found to be so 
perfectly indelible as not to be removed even with indiarubber. 

Picture - Cleaning. — The most simple application for oil 
pictures is water and plenty of it. If the coats of varnish are 
very thick, the scraper may remove a good deal. Spirits of 
wine and turpentine may be applied ; but the scraper, spirits of 
wine and turpentine, will attack the paint as well as varnish, 
and the art of picture-cleaning is to stop action before you 
arrive at the paint. Water will stop further action of the 
spirits. Experimentalize only on a corner or an unimportant 
part of a picture. Many good and valuable pictures have been 
rendered worthless by the process of what is usually called 
cleaning, particularly under the infliction of spirits of wine, 
turpentine, home-made varnish, &c. If the picture be an old 
one, it is usual to begin by rubbing off the old varnish, which 
is done with the fingers, rubbing gently and evenly in small 
circles over the whole picture, beginning with a little dust on 
the fingers, after which the light powder — the remains of the 
gum of the old varnish — will soon appear. Care must be 
taken not to touch the colour of the picture. Then wash with 
clear water, and when quite dry, varnish. It is preferable in 
all respects to buy varnish at the artist's colour-shops. If there 
is not any old varnish on the old picture, first wash the picture 



200 DRA WING AND MODELLING. 

with warm rain-water, using a soft sponge, and then carefully 
with a lukewarm solution of a quarter pound of soft soap in a 
quart of rain-water. 

Varnishes for Prints and Water-Colour Drawings. — The 

printing must be thoroughly dry. Size made by boiling an ounce 
of best isinglass in a pint of water should then be applied quickly 
to the surface. This may be done in two ways, the latter being 
preferable. First brush the size over the surface of the picture 
rapidly with a broad camel's-hair brush ; second, having poured 
the solution into a flat dish, pass the drawing quickly through 
the fluid, so that the whole of both surfaces may be thoroughly 
wetted. Lay the drawing carefully upon a flat board to dry ; 
any colourless varnish may then be applied. If isinglass can- 
not be procured, clear gum-water will answer almost as well. 

A good and cheap Varnish for general use, and one which 
dries in a very short time, may be made of the best wood 
naphtha i pint, gum shellac 2 oz., gum sandarac 2 oz. ; pound 
the ingredients in a mortar, and pour on the naphtha, shaking 
it up often. When dissolved, filter through fine muslin, and 
the varnish will then be fit for use. If too thick, add more 
naphtha. 

Another Varnish, fitted for prints or drawings, is the follow- 
ing : — Give the article one or two coats of gum arable, dissolved 
in water, about 2 oz. to a pint ; a coat of crystal varnish will 
complete the operation. The crystal varnish may be purchased 
at any of the oil and colour shops. Turpentine varnish is 
often used in lieu of crystal, and is much cheaper. Fine 
parchment size, or isinglass, will be found preferable to gum- 
water. The best varnish is clear pale copal, dissolved in recti- 
fied spirit, which is easily done by heat. A small quantity of 
shellac will harden the varnish, but it communicates a brown- 
ish tinge. A varnish composed of shellac alone, dissolved in 
spirit, is so hard, that if a coat of it be laid upon a card, it may 
be written upon with a pen and ink, and rubbed out again with 
a sponge, without leaving any perceptible trace. 

Another Varnish. — Balsam of copaiba 4 parts, powdered 
copal I part. Mix, and keep it in a close vessel at a heat of 
150° Fahr., until the gum is dissolved; then thin it with tur- 
pentine. 

Size for Prints or Drawings before Colouring. — Best pale 



DRAWING AND MODELLING. 201 

glue and white soap, of each 2 oz., hot water 30 oz. \ dissolve, 
and add powdered alum i oz. 

Painters' Cream. — Painters who have long intervals between 
their periods of labour are accustomed to cover the portions 
painted with a preparation which preserves the freshness of the 
colours, and which can be removed when they resume their 
work. This is the preparation : — Take of clear nut oil 3 oz. ; 
mastic in tears, pulverized, \ oz. ; sal saturni, in powder, ace- 
tate of lead, I oz. Dissolve the mastic in oil over a steady 
fire, and pour the mixture into a marble mortar over the 
pounded salt of lead ; stir it with a wooden pestle, and add 
water in small quantities till the matter assumes the appear- 
ance and consistence of cream, and refuses to admit more 
water. 

Modelling. — Rice flour, mixed thick with a little cold water, 
and warmed over a fire, may be moulded into busts, figures, 
bas-reliefs, ornaments, &c., very readily. When dry and hard, 
images thus formed may be polished, and will be found very 
durable. 

Gypsum — Plaster of Paris. — This substance possesses 
some peculiar properties. It consists of sulphuric acid, lime, 
and water; its composition, or rather the proportion of its 
component parts, being similar to that of alabaster. Its abund- 
ance in the tertiary basins around Paris has given it the name 
of plaster of Paris. It is found in Nova Scotia in profusion in 
the lower carboniferous rocks. It is produced by the decom- 
position of iron pyrites and limestone in juxtaposition. It is 
formed wherever sulphuric acid is generated, and comes in 
contact with carbonate of lime. Crystallized gypsum is called 
selenite, and the ancient Romans are said to have used it as 
glass. It is often coloured by oxide of iron to grey, brown, 
red, yellow, and even black. It is used extensively for making 
plaster casts, and for stucco. It is prepared for these purposes 
by calcining, which is simply heating it in kilns or kettles until 
the water is expelled. It is then a fine powder, like wheat 
flour, and to be used, must have the water which it previously 
held returned to it. To preserve it from contracting the mois- 
ture in the atmosphere, it should be kept as nearly air-tight as 
possible. Much of the plaster or gypsum sold in the market 



202 DRAWING AND MODELLING, 

is deteriorated by careless handling and packing. When mixed 
with water, it " sets " quickly, and no time should be lost be- 
tween the mixture of the gypsum and the taking of the cast. 
Of late years it has been a favourite substance with dentists 
in taking casts of mouths to which teeth were to be fitted. We 
know of no way by which this substance, being once used, can 
be brought to its original state. It is used to some extent in 
glazing porcelain ; but it is more largely used as a fertihzer of 
soils than for any other purpose. Containing a large propor- 
tion of sulphate of lime, it is extensively used as a manure. It 
is excellent for grass of all kinds, furnishing just the nutriment 
needed. 

Fictile Ivory. — This ivory is prepared by intimately mixing 
and passing through a fine sieve superfine plaster of Paris and 
Italian yellow ochres — half an ounce of the latter to every pound 
of the former, and then forming a plaster cast of these ingre- 
dients in the usual way. This cast is first dried in the open 
air, and then carefully in an oven ; after which it is soaked for 
1 5 minutes in a mixture consisting of equal parts white wax, 
spermacetti, and stearine, heated a little above the melting- 
point. When removed from this, the cast is allowed to drain, 
and before it is cold any excess of the wax, &c., which may 
remain in the crevices, is brushed off by means of a painter's 
sash-tool ; and as soon as it is quite cold, it is polished with 
a tuft of cotton wool. 

Plastic Moulding {Parkes* Patent). — To make about i lb. 
of this compo, melt together ^ lb. each of wax and deer's flat ; 
then dissolve 19 or 20 grains of phosphorus in 300 grains of 
bisulphide of carbon. Keep the wax mixture barely melted, 
and add the phosphorus solution slowly to it. Briskly stir the 
fat while pouring it in at the bottom of the melted mixture by 
means of a vessel with a long spout to prevent it inflaming. 
It is highly dangerous to spill the phosphorus compo where it 
can come in contact with wood, paper, rags, &c., as after a 
lapse of even many hours they will often burst into flame. 

Vegetables, Insects, Small Birds, Frogs, Fish, &c., Cast 
in Plaster Moulds. — Provide a trough of boards, nailed to- 
gether so as not to let the water run through the joints ; sus- 
pend in the trough, by thread or Holland twine, in several 



PHOTOGRAPHY, 203 



places, the vegetable, plant, insect, &c., which you would cast, 
which, being performed, mix 4 parts of plaster of Paris, and 
2 parts of fine brick-dust with common water, to the consist- 
ence of cream, and with this cover the thing intended to be 
cast, observing not to distort it by any means from its natural 
position. When you have filled your trough, let it harden by 
placing it near the fire by degrees till you can make it red hot ; 
then let it cool, and with a pair of bellows blow and shake as 
much of the ashes out of the mould as you can. You must 
now put a small quantity of quicksilver into the mould, and 
shake it, in order to loosen every part of the ashes therein ; 
also to make a passage through where the strings were tied, in 
order to let the air out when you pour in your metal. 

Metal for the above Work. — Take of grain tin 6 oz., bismuth 
2 oz., and lead 3 oz. Melt them together in an iron ladle, and 
you may cast in the above mould to your satisfaction. You 
may combine the above ingredients in such proportions as to 
compose a metal that will melt in boiling water, thus — Sir 
Isaac Newton's fusible metal is composed of 8 parts bismuth, 
5 parts lead, and 3 parts tin ; this alloy melts at 212°. Rose's 
alloy is still more fusible ; it is 2 parts bismuth, i part lead, 
and I tin, and melts at 201*^. Dr Dalton's fusible alloy — 3 
parts tin, 5 parts lead, 10^ parts bismuth — melts at 197°. 
The addition of a little mercury makes it more fusible, and fits 
it to be used as a coating to the insides of glass globes. 

Vaamishing Plaster Casts. — Plaster casts can be varnished 
by a mixture of soap and white wax in boiHng water. A \ oz. 
of soap is dissolved in a pint of water, and an equal quantity 
of wax afterwards incorporated. The cast is dipped in this 
liquid, and, after drying a week, is polished by rubbing with 
soft linen, producing a polish like marble. If to be exposed to 
the weather, saturate the casts with linseed oil, mixed with 
w^ax, or resin may be combined. In casting the plaster, use 
spring-water and gum arabic. 

To Print on Canvas. — Prepare the canvas by washing it 
over with a solution of bicarbonate of soda in water, and rub 
it until it is evenly wet. Wash with water to remove the soda, 
and then lay a piece of albumen paper, of the size you wish to 
make the print, face down upon it, and rub it well to secure 
contact all over. Lift up the paper and remove the bubbles, 



204 PHOTOGRAPHY. 



if there should be any, with a brush. After drying, coagulate 
the albumen by pouring on some strong alcohol ; dry again, 
silver with a 40-grain silver solution, slightly acid ; print, and 
fix in hypo. 

Cyanide of Silver. — Break up an old silver coin, say 6d. ; 
put it into a porcelain cup, and cover it with nitric acid un- 
diluted ; set it on a fire-shovel over a slow fire, or make it warm 
by any convenient means, and the silver will soon dissolve ; 
add acid occasionally, if necessary ; when dissolved, fill the cup 
nearly full with clean rain-water, and let it settle for a few 
minutes. Pour off the clear liquor into a pint glass tumbler or 
jug, add a tablespoonful of clean common salt, chloride of silver 
will be the result. Pour off the clear liquor (which may be 
thrown away), add water to the precipitate, and agitate it well 
with a glass rod, but by no means with a metal one ; pour 
away the liquor as before ; wash again ; by these means the 
salt will be washed out. Now dissolve ^ oz. of cyanide potas- 
sium in a half gill of rain-water warm ; when dissolved, and 
the liquor cold, add it gradually to the dissolved silver, and a 
good plating liquid, consisting of the double cyanides of silver 
and potassium, will be the result. To use the solution, clean 
the article well, immerse in the solution in contact with a small 
piece of clean zinc. With nitrate of silver he can proceed 
thus : Dissolve the crystals in water, add to the solution gra- 
dually the solution of potassium, till a precipitate has fallen, 
then add more cyanide until that precipitate is redissolved, — 
a much cleaner way than the others, and something purer too, 
but not so cheap. 

Instantaneous Photography. — Herr Metzger is of opinion 
that success in instantaneous photographs depends more upon 
the excellence of the apparatus and chemicals employed, and 
rapidity of manipulation, than on the practice of any particular 
theory or process. Of the many descriptions of collodion, that 
prepared according to Dr Liesegang's formula appears to him 
best suited for instantaneous photography ; for although (he 
says), I have been successful in obtaining good results with 
mixed collodions, I prefer to use a material freshly prepared, 
together with a neutral 10 per cent, silver bath. For develop- 
ing I employ the following formula, adding as much alcohol as 



PHOTOGRAPHY, 205 



maybe necessary to make the solution flow evenly over -the 
plate, viz. : — 

Water, . . . . .100 grains. 

Sulphate of iron, . . . . 5 >, 

Acetic acid, . . . . 3 ?? 

My negatives are intensified with pyrogallic acid, which is used 
very carefully, in order that the harmony of the pictures may 
not be destroyed. The plate should be exposed as soon as 
possible after its exit from the silver bath, and developed 
immediately after exposure ; the object to be photographed 
must be lighted as strongly as possible ; and if direct sunlight 
is not present, all false lights and reflections are to be carefully 
avoided. March and October are the most favourable months 
for instantaneous photography. 

Instantaneous Pictures by Artificial Light. — Mr Thomas 
Skaife has patented a process to obtain an iastantaneous flash 
of artificial light for the production of small portraits. The 
specification is as follows : — These improvements relate to the 
construction of an apparatus for igniting and burning any 
powder or other composition either in a solid or liquid state, the 
flame or flash of which, being sufficiently actinic, is applied for 
the production of photographic pictures. For this purpose the 
said apparatus consists of a platform of metal or other incom- 
bustible substance perforated with one or more touch-holes 
fixed, attached to, or supported by, a spring or springs in such 
a manner as to permit of its being easily vibrated or thrown 
into a tremulous motion by the touch of the finger or other 
appliance. Connected with or attached to the platform is a 
parabolic or other reflector pierced with a groove, through 
which communication is made with one end of the platform, 
by which it may be touched or struck, so that by means of the 
aforesaid springs it may suddenly vibrate. The deflagrating 
powder or other explosive actinic substance, being placed or 
strewn upon the perforated platform, is suddenly brought into 
contact with a light from an ordinary spirit-lamp, or such like 
substance, preferably placed underneath it ; at the same instant 
the platform, being thrown into vibration, communicates this 
motion to the particles of the powder or other substance to be 
ignited, the result of which action is that every particle explodes 



2o6 PHOTOGRAPHY. 



or is ignited simultaneously, and producing a flash of light 
which, acting upon a sensitized plate in an ordinary camera, 
produces the picture of any object placed before it. When the 
picture of a near object is required, the powder may be placed 
over a touch-hole ; if the picture of a distant object is to be 
taken, then the powder may be distributed over the platform 
and over several touch-holes, to all of which the light may be 
applied. Having now described the nature of my invention, 
and the principles by which it is carried out in practice, I wish 
it understood that what I claim and desire secured to me by 
the before in part recited letters patent is, the use of a vibrat- 
ing platform or table with or without a reflecting mirror, for the 
purpose of producing, by means of vibration among its particles, 
an instantaneous combustion of any actinic powder or other 
deflagrating or easily flammable substance, when used for the 
purpose of obtaining photographic pictures substantially as 
herewithin described and set forth. 

Photographometer. — This apparatus is intended to record 
the angular position of objects situated around a given point. 
It is automative, and very simple. The record is made by 
photography, and the camera used, with the exception of cer- 
tain additions, does not differ much from the ordinary kind. 
The objective, which is that usually employed by photographers, 
is mounted vertically on a circular platform capable of rotating, 
by means of clockwork, in a horizontal plane. The picture is 
formed, not in a vertical plane, as in ordinary cases, but in a 
horizontal ; and therefore the rays, passing in through the ob- 
jective, are deflected 90° by means of a reflecting prism, so as 
to fall on the sensitive surface, which is collodionized glass, 
and is placed in such a way that its centre corresponds with 
the point at which the centre point of the diaphragm would be 
represented. To prevent a number of confused images, super- 
* imposed on each other, being formed during the rotation of the 
objective, an opaque screen, having a narrow oblong opening, 
the medial line of which passes through the axis of rotation, 
is placed over the whole of the sensitized surface, and revolves 
along with the objective. The result of this arrangement is 
the production on the sensitized plate of images of the different 
points that lie around the observer ; the angles formed by lines 
joining the centre of the plate, and the different objects being 



PHOTOGRAPHY. 207 



exactly the same as those formed by lines joining the centre of 
the instrument and the objects themselves. The position of 
the objects thus accurately obtained may be transferred to 
paper, &c., in the ordinary way. As different velocities of 
rotation may be suited to different purposes, three different 
velocities may be obtained by means of a regulator. And as 
it may be wished to mark down only certain points of the 
panorama, an arrangement is made which secures the attain- 
ment of this object. Should it be desired to observe not 
different points, but successive changes at the same point, the 
objective and the screen are disconnected, so that only the 
latter revolves ; the successive appearances at the same point 
are then recorded in succession in a circle round the sensitized 
plate. 

Hyposulphite of Ammonia for Fixing. — The question has 
repeatedly been asked as to whether the use of hyposulphite of 
ammonia might not be found more efficient in fixing than that 
of the soda salt. In some of Sir John Herschel's earliest ex- 
periments with the hyposulphites as solvents for silver salts, 
he used hyposulphite of ammonia, but we have no record of its 
use for photographic purposes. Mr T. H. Redin, a skilful 
amateur photographer, has made some good prints fixed with 
hyposulphite of ammonia. It was used in the same manner as 
the soda salt. There is good reason to believe it will be valu- 
able in securing more perfect fixation than has hitherto been 
secured, and will so be conducive to permanency. Hyposul- 
phite of soda does not perfectly dissolve albuminate of silver, 
but leaves some portion of the silver salt in the whites of the 
print. The new salt effects the perfect removal of the silver. 

Recovering Silver. — Let the amateur put his powder, sand 
and all, into a glass or earthenware jar, and pour over it some 
aquafortis, diluted wi:h seven times its bulk of water, consider- 
ably more than enough to cover the sand, &c. Stir well with 
a glass rod or piece of charcoal or wood, so long as any fumes 
are given off. Allow it to settle, and pour off the clear ; what 
remains as sediment may be thrown out, as it is only sand and 
dirt, the silver and copper being dissolved out. To the blue 
liquid portion add muriatic acid (spirit of salt) so long as a 
white curdy precipitate is formed and falls. Pour off the liquid 
portion, and throw it away as useless. Wash the precipitate 



2o8 PHOTOGRAPHY, 



frequently with water until it is tasteless, or is in no way acid, 
without losing any. Then dry it at a low temperature unex- 
posed to light. The remaining powder is tolerably pure 
chloride of silver. If it is desired to obtain metallic silver 
from this, the chloride, the following process is both elegant 
and extremely simple : — Put the chloride of silver into a glass 
tumbler with some slips or chippings of thin sheet zinc. Then 
add some oil of vitriol diluted with seven times its bulk of 
water, sufficient to saturate and cover the contents of the glass, 
stir with a slip of sheet zinc until the contents assume a homo- 
geneous grey colour. Remove the clippings of zinc, and wash 
the remaining powder with water until it ceases to be acid ; 
dry it, and what remains is chemically pure metallic silver. If 
wanted in a solid condition, fuse it in a crucible with a little 
powdered charcoal, when it will assume the brilliant white 
metallic lustre characteristic of the pure metal. If he wishes 
for the alloyed metal he has lost, he may get it in a much 
simpler way. Let him precipitate the powder into a shallow 
glass or earthenware vessel full of w^ater. The metal being the 
heaviest will fall to the bottom first. By removing the super- 
ficial layer of sand and dirt, and repeating the process several 
times, he will obtain the lost metal composed most likely of a 
mixture of silver and copper. 



Silver, How to Save. — The waste silver is an item of con- 
siderable importance to every photographer, and an apparatus 
for saving it must therefore be useful. A " Practical Photo- 
grapher ^' thus explains his plan : — I made my sink with more 
dip or inclination from horizontal than is usual, in order to 
have the water flow off more rapidly ; then in the lowest corner 
I inserted two lead pipes close together, one of them leading 
into the waste drain, the other into a tank or barrel under the 
sink, which should be of sufficient size to contain the washings 
of one day's work. These vents can be opened or closed at 
pleasure, by moving a lever attached in such a manner as to 
close one while it opens the other, and vice versa ; or the pipe 
may be simply closed with a cork, which can be shifted from 
one to the other as is desired. This is not so convenient a 
method as the other. Whenever the washings contain silver 
or gold, I allow them to pass into my tank ; but when worth- 
less, by shifting my lever I let them run to waste. I have a 



PHOTOGRAPHY. 209 



faucet inserted into the tank about one foot from the bottom, 
and after the day's work is over, I draw off two or three gallons 
of the contents of the tank, and add to it sufficient cream of 
lime or whitewash to neutralise the whole, and pour it back. 
If this operation is rightly managed, the water can be drawn 
from the tank perfectly clear after standing over night. The 
cream of lime is best prepared by selecting the purest lumps 
of quicklime, and slacking them carefully with boiling water 
(sufficient water should be added, and the mass constantly 
stirred, to prevent its getting too hot or dry in spots, in which 
case it will be lumpy and coarse) ; after cooling, it should be of 
the consistence of thick cream, and may be kept in an earthen 
or stone jar for a long time, if properly covered, so as to protect 
it from the carbonic acid of the air. It will be found very 
convenient for many purposes. As fast as the tank fills up 
with sediment to the faucet, I dip it out and dry it, and reduce 
the silver by any method that may be preferred. The opera- 
tions are easy and economical, and the saving of silver con- 
siderable. 

To use Old Baths, and Save the Silver. — A correspondent 
of the American Jow^nal of Photography says — " For several 
months past I have been using an old silver bath for silvering 
albumen paper. It had been used a long time, and was in 
such a condition that it would not work without considerable 
J;rouble, so I added pure water sufficient to precipitate the 
iodide ; then, after filtering, I added silver in crystals until the 
solution was strong enough for silvering paper ; then a sufficient 
quantity of aqua ammonia. It seems to give as good results 
as to use the crystals. There is more economy in this process 
than in * doctoring up ' an old bath ; for any one who makes 
photographs uses more silver for silvering paper than for any 
other purpose, and by this process old baths that ' will not 
work' can be used up." 

Nitrate of Silver Bath for Negatives, Preparation and 
Management of. — This bath, which exercises such an impor- 
tant influence on the quality of photographs, is simply composed 
of nitrate of silver dissolved in water. When dissolved, it 
should be nearly neutral, the deviation from neutrahty being in 
favour of acidity. In much of the nitrate of silver of commerce 
there is imprisoned a certain quantity of nitric acid, which, 

o 



210 PHOTOGRAPHY. 



when the crystals are dissolved in distilled water, renders the 
solution acid in too great a degree. If the ordinary commer- 
cial crystals be employed, crush them into a coarse powder and 
apply heat, which drives off the excess of nitric acid. Then 
dissolve them in distilled water, in the proportion of 35 grains 
of the crystals to i oz. of water. Use only half of the water 
intended to be added, and then add (previously dissolved in a 
small quantity of water) about 3 grains of iodide of potassium. 
The iodide of silver formed by this addition will be dissolved, 
after which add the remaining half of the water, and then filter. 
With most of the samples of nitrate of silver no other prepara- 
tion is required. If, however, the picture taken prove deficient 
in clearness, add one or two drops of a very diluted solution of 
nitric acid, composed of half a drachm of the acid in an ounce 
of distilled water. This for a bath of 12 or 14 ounces will, in 
most instances, prove sufficient. An efficient method of making 
a neutral bath is to dissolve i\ oz. of crystals of nitrate of 
silver in 4 oz. of distilled water, and, when dissolved, to add to 
it 4 grains of iodide of potassium dissolved in a drachm of 
water ; shake, and add 16 oz. of distilled water. Now add to 
thfs a small quantity of oxide of silver (prepared by pouring 
a solution of caustic potash into a solution of nitrate of silver, 
and washing well the precipitated oxide) until the solution, 
already turbid from iodide of silver, is of a dirty brown colour. 
The quantity of oxide added is of no consequence. When the 
solution is filtered, it will be found very slightly alkaline, in 
which condition it would yield foggy pictures. Previous, how- 
ever, to using it, 5 minims of the following diluted acid should 
be added : — 

Nitric acid ( 1-50), . . . 6 minims. 

Distilled water, . . . i ounce. 

The bath is now ready for use, and will prove to be in the most 
perfect condition. When, from repeated use, a bath becomes 
disordered, and produces foggy pictures, it should be tested for 
acidity by immersing in it a slip of litmus paper. If it do not 
turn red after being immersed for some time, add some of the 
dilute acid, given above, until it do so. Fogging in an old 
bath is easily cured by rendering it slightly alkaline (with 
diluted ammonia, for example), and exposing to sunlight for 
some time. By this means all organic matter is precipitated. 



PHO TO GR A PHY. 2 1 1 



After filtration, one or more drops of the diluted nitric acid will 
be found necessary to restore the requisite acidity. Some 
baths, which from use or abuse have failed to yield clean pic- 
tures, have had their working qualities restored by adding a 
few drops of a solution of cyanide of potassium, which in the 
precipitation of the cyanide of silver formed carries down the 
offending organic matter. Each photographer seems to have 
his own favourite method of restoring the bath when disorga- 
nised ; but as the restoration occasionally involves a loss of 
time, it is desirable that two baths be kept in stock, one 
relieving the other. 

Cheap Collodion Filter. — Procure two new stoppered 
bottles, wide-mouthed, so that one neck will fit, after grinding 
with sand and water, into the other, inverted ; then knock out 
the bottom of the inverted bottle, and grind the edges ; then 
fit a bung, air-tight, to act as stopper; cut a funnel-shaped 
cork to fit in the neck of the inverted bottle, and run a quill up 
one side of the cork to allow the air to pass through ; cement 
it tight with sealing-wax inside the bottle ; put your cotton wool 
into the bottle, and commence to filter, which will answer the 
same as those sold at 7s. 6d» 

Burnt-in Photographs. — Take saturated solution of bi- 
chromate of ammonia, 5 parts ; albumen, 3 parts ; honey, 3 
parts ; and dilute with 20 parts of water. Pour this over a 
glass or enamelled plate, and, after drying, expose for a few 
seconds under a glass transparency. Now remove to a damp 
room, and brush over the surface some enamel colour until the 
image appear. Fix with alcohol, to which a little acetic acid 
has been added, and when dry rinse in water, dry again, and 
place in a mufHe to burn in. 

Fixing Prints. — In various scientific journals it is stated 
that, if toned prints be placed in a five per cent, solution of 
common salt, which is then to be raised to the boihng-point, 
and left ten minutes, they will be perfectly fixed, and merely 
require washing. A very careful washing is necessary, for any 
trace of a chloride left in the print tends to destroy it. 

Photography on Silk. — Immerse the silk in water, i oz. ; 
gelatine, 5 grains ; chloride of sodium, 5 grains. Hang it up 



212 PHOTOGRAPHY. 

to dry ; then float for half a minute on a fifty-grain solution of 
nitrate of silver ; dry, print, tone, and fix as usual. 

Waterproof Enamel for Card Photographs. — The follow- 
ing is a good substitute for the collodion transfer process, and 
much easier of application : — First apply with a brush to the 
surface of the card a solution of gum arable, of sufficient 
strength to give considerable gloss when dry. As soon as dry, 
apply a coating of plain collodion as in coating a plate. If the 
collodion is not very tough, two or three coatings may be 
appHed to advantage. Finish by passing the card through a 
roller, and you have a fine gloss. Take care not to have the 
gum solution too thick, or the surface will crack when dry, 
though there is but little danger if the collodion is applied soon 
after the gum is dry. Gelatine, instead of gum arable, will 
answer, though it gives hardly as much gloss. 

To Remove Nitrate of Silver .Stains from the Skin. — 

Cyanate of potassium is dangerous, but the following may be 
safely employed : — Make a pretty strong mixture of solutions 
of bichromate of potash and sulphuric acid — say two parts 
saturated solution of bichromate, three of water, or one of sul- 
phuric acid. Wash the hands well with this, then rinse them 
off, and have at hand some Lugol's solution, which for this 
purpose may be made as follows : — Iodide of potassium, \ oz.; 
iodine, 40 or 50 grains; water, 10 oz. After rinsing off the 
bichromate, wash the stains with this solution. Under its 
action they rapidly lighten in colour ; but the hands become 
stained deep orange colour by Lugol's solution. Finish them 
with some negative hyposulphite, which clears off all the colour 
that remains. 

Washing Apparatus. — Attach the prints to a surface of 
perforated or woven material arranged round a drum, which 
revolves in a trough containing water, only a portion of the 
drum being, however, submerged. On communicating a rapid 
motion to the drum, -the prints are alternately immersed in 
water, and then whirled round with sufficient force to drive off 
the moisture, thus securing an effectual application to the alter- 
nate washing and draining principle which, on the principle of 
centrifugal force, is recognised as desirable in getting rid of 
moisture. 



PHOTOGRAPHY. 213 

Cleaning Glass Plates. — (i.) Soak them in a solution 
made by dissolving an ounce and a half of bichromate of potash 
in a pint of water, and adding about 6 drachms of sulphuric 
acid. Plates soaked in this solution for a few days, and then 
well washed, will be almost as good as new. (2.) Soak them 
all night in a strong solution of potash and water. Then place 
a plate on a flat piece of washing cloth, and with a tuft of the 
same rub each side and the edges with a saturated mixture of 
common salt and tripoli. Set the plates up to dry, and clean 
with a first and second towel kept for the purpose, or wash the 
plates, adding at first a little nitric acid. The following mix- 
ture on a cloth and tuft of its own, giving a final rub wherever 
the fingers have touched, is recommended : — Old collodion, 
I oz. ; spirit of wine, 2 oz. ; water, \ oz. ; tripoli, i oz. ; iodine, 
15 Z^' Shake and leave on plate till wanted. (3.) Make a 
solution of nitric acid, i part ; distilled water, 3 parts. Let 
the plates stand in this for three days, then rub them well with 
a cork while wet, and swill them in several clean waters. 

To Clean Silver Plates. — Dr C. Calvert gives the follow- 
ing as a good plan : — Plunge the plate for half an hour in a 
solution of I gallon of water, i lb. hyposulphite of soda, 8 
oz. muriate of ammonia, 4 oz. liquid ammonia, and 4 oz. 
cyanide of potassium ; but as the latter substance is poisonous, 
it can be dispensed with if necessary. The plate being taken 
out of the solution is washed, and rubbed with a wash-leather. 
The same plan may be adopted for all kinds of silver articles 
or thickly-plated table-ware. 

To Copy Cartes without Reduction of Size. — Place the 
carte or other object to be copied at a distance from the lens 
of twice its equivalent focus, the sensitized plate being placed 
at an equal distance. Thus, if the lens be of six inches equi- 
valent focus, the distance between the picture being copied and 
the sensitive plate on which its image is received will be 24 
inches, the lens occupying a place midway between, thus having 
its centre 12 inches from both the object being copied and the 
surface on which it is copied. 

Double Photographs. — These may be taken with an ordi- 
nary camera in the following way : — Against a perfectly black 
background, take a photograph of the person, only a little to 



214 PHOTOGRAPHY, 



one side of the plate. After it has had the proper exposure, 
put the cap on the lens, but do not shut down the slide ; then 
pose the person again according to taste — taking care that his 
image on the plate shall not overlap the previous image — and 
expose again, and the double photograph is taken. The first 
picture will not suffer from a second exposure by reason of the 
dark background being a negation of light. To insure a good 
picture the background must be perfectly black, and the object 
well illuminated. An acid developer is preferable. 

New Filtering Apparatus, — An economic filter and per- 
colator has been devised by an ingenious combination of syphon 
tube and filtering medium. Any test liquid may be drawn 
from a bottle in a state of limpidity, and if necessary, returned 
again turbid to the stock for refiltration. By slight modifica- 
tions the apparatus is used for filtering alcoholic ethereal or 
caustic alkaline solutions out of contact with the air, and it can 
be adapted to a water-bath so as to admit of the filtration of 
gelatinous liquids. The apparatus is specially contrived for 
use amongst photographers ; but it is evident that there are 
many uses in chemical, pharmaceutical, and manufacturing 
laboratories to which this apparatus can be economically 
applied. 

Transferring Photographs to Metals for Printing. — Mr 

Woodbury of Manchester has discovered that gelatine, when 
dissolved in hot water, if mixed with bichromate of potash or 
ammonia, dried and exposed to the action of Hght, be- 
comes insoluble — a result due to the decomposition of the 
alkaline bichromate and the liberation of chromic acid. It will 
be seen that a coat of the bichromated gelatine on a glass or 
metal plate placed under a negative and exposed to light, 
would, when subjected to the action of hot water, be dissolved 
away in some parts, and in other parts unaffected, thus pro- 
ducing a photographic positive /;/ relief. Acting on these 
facts, Mr Woodbury takes the image in relief so produced, and 
either by mechanical pressure with some soft metal, such as 
type metal, or by the usual process of electrotyping, produces 
an intaglio impression therefrom. A properly-prepared ink, 
formed with gelatine and some black or other coloured pigment, 
is then passed over the plate, with which the impression is 
filled up even to the surface. The gradations of 7'elief in the 



PHOTOGRAPHY, 215 

bichromatic gelatine print form gradations of depth in the metal 
intaglio, in which again the ink, being transparent, forms gra- 
dations of blackness proportioned to its varying thicknesses. 
A modification of this plan is, in fact, the " Woodbury Pro- 
cess.'' 

The Magnesium Light. — In reference to this wonderful 
mode of illumination, Professor Schrotter, of the Vienna Aca- 
demy of Sciences, has obtained some important results, of 
which the following may be taken as an epitome \- — The mag- 
nesium light promptly and powerfully produces fluorescent as 
well as photographic effects. This light contains an extraordi- 
nary quantity of ultra-violet rays, the spectrum of which is at 
least six times as long as that of the luminous portion. Crys- 
tallized platino-cyanide of barium, finely powdered or made 
into a paste with gum, so that it can be fixed on paper, gives 
a powerful fluorescence when exposed to this light. All sub- 
stances which become luminous by isolation acquire this pro- 
perty in the highest degree by a few seconds' exposure to 
burning magnesium, whilst with the sun it takes five to ten 
minutes to produce the same effect. The light re-emitted by 
these bodies has no photographic power, the absorbed chemical 
rays being degraded to purely luminous ones. If a piece of 
burning magnesium wire is brought near to the sides of a white 
glass cylinder, filled with equal parts of hydrogen and chlorine 
gases, drops of hydrochloric acid will be seen to condense on 
the portion of the cylinder nearest the wire. If now a second 
piece of wire is burnt on the opposite side of the glass, an 
explosion takes place almost instantaneously. By means of the 
magnesium light instantaneous photographs may be taken. 

Artificial Light for Photographers. — Professor Falkland 
recommends peroxide of nitrogen, which may be thus pro- 
duced : — A light bottle is taken, of about a pint capacity ; it 
is fitted with a cork, through which passes a glass tube, bent 
to a right angle a little above the top, and the end drawn out 
so as to form a jet, the tube being bent like the letter U, so 
that the jet looks upward. The only other essential vessel is 
a test-tube, or narrow beaker, into which the U tube can easily 
dip. Fragments of copper, either plate or wire, are placed in 
the bottle, with a mixture of one part strong nitric acid and two 
of water. The cork, with its tube, is replaced ; the little beaker 



2i6 PHOTOGRAPHY. 



is placed in a vessel of warm water, and the bottle is placed so 
that the bent portion of the tube dips into the beaker. As soon 
as the gas comes freely through the jet, some bisulphide of 
carbon is poured into the beaker. The hot water with which 
the latter is surrounded quickly vaporises the bisulphide, 
which, when set fire to, burns at the mouth of the beaker with 
its usual blue lambent flame ; but from the gas jet upwards for 
an inch or more, according to pressure, arises a briUiant cone 
of flame, giving intense light, and possessing great actinic 
power. The current of gas should be tolerably rapid, and the 
bisulphide well heated to ensure the best effect, and it should 
not be forgotten that the burning bisulphide gives off abundance 
of deleterious fumes of sulphurous acid. 

Easily-prepared Photographic Varnishes. — Procure some 
good gum benzoin ; place it in an earthenware or metal cap- 
sule, and apply moderate heat until it is perfectly fluid. Then 
pour it upon the bottom of a cold plate, and, when it has been 
quite cold, it may be broken off in pieces. To form the varnish, 
the following recipes are good. The second is more expensive 
than the first, but a little better : — 

(i.) Dissolve in 8 oz. of methylated alcohol i oz. of the 
fused benzoin and 20 grains of sandarac ; then add 20 drops 
of mastic varnish, made by melting gum mastic, and adding 
turpentine to it whilst in a fluid state. The impurities will soon 
settle, and the varnish is ready for use. 

(2.) Fused benzoin, ... \ ounce. 

Sandarac, . . . 

Jalap resin. 
Methylated alcohol. 
Mastic varnish. 



10 grams. 

\ ounce. 

8 fluid ounces. 
20 drops. 



Should either of these varnishes be too thick, or become so by 
use, they may be diluted with a little more spirit. Should the 
spirit be too strong, which may be known by its partially dis- 
solving the collodion film, a very few drops of water may be 
added. When using either of the above preparations, the 
negative may be varnished twice without any danger. This 
enables us to touch out any spots, &c., on the negative, and 
then revarnish. 

(3.) M. Bussi first brushes the prints over with a solution of 



PHOTOGRAPHY. 217 



gum arable, and when this is dry, appUes a coating of collodion. 
The following are the proportions recommended : — i. Clear 
transparent gum arable, 2 5 grammes ; distilled water, 1 00 
cubic cents ; dissolve and strain. 2. Gun cotton, 3 grammes ; 
alcohol, 60 grammes ; ether, 50 grammes. By this double 
varnish the preservation of the proofs is insured. 

Fixing Solution. — A good fixing solution should consist of 
4 oz. of hyposulphite of soda in a pint of water, and should 
always be used fresh. The number of prints of a given size 
which may be safely fixed in a definite quantity of hypo-solution 
cannot be absolutely stated. Theoretically, about three parts 
of hyposulphite of soda will be required to dissolve one of 
chloride of silver. One whole sheet of sensitive paper has 
been calculated to contain about from 25 to 30 grains of 
chloride of silver. On this theory about half a dozen sheets of 
paper might be fixed by i oz. of hyposulphite of soda. In 
practice, however, so many other circumstances interfere, that 
perhaps not more than one-fourth of that number ought to be 
fixed in the quantity. In very cold weather, the solution is 
comparatively inactive ; it is well, therefore, to raise the tem- 
perature to about 60° Fahr. Thin Saxe paper will generally 
be fixed in new hypo, of the strength named, in about ten 
minutes ; thick Saxe will require fifteen minutes ; thin Rive 
paper about fifteen minutes, and thick Rive about twenty 
minutes. A slightly albumenized paper will be fixed more 
rapidly than a highly albumenized sample ; the principle being, 
that the more horny and repellent the surface, the longer the 
time of immersion. Complete immersion and constantly moving 
about are imperative. 

Focusing Screen. — Take a piece of patent plate-glass, the 
size required, lay it down on a perfectly flat bench or board, 
with a small tin tack or two on each side of the glass to keep 
it in place ; then take a pinch of the Wellington knife-powder, 
which will be enough to grind a score of screens. Apply the 
powder to your glass with a few drops of water, and mix till 
about as thick as cream ; then take a piece of thick plate-glass 
about I inch square, and grind the surface of ybur glass with 
a regular motion of the hand slightly bearing on till you get a 
good face, which will take from half an hour to one and a half 
hours according to the size of screen. Apply fresh powder and 



2i8 PHOTOGRAPHY, 



water at times, and to see how you are getting on with it, wash 
in clean water, and dry very steadily before a fire or in the 
sun ; and if the screen has not a nice regular clean face apply 
the same means over and over again if required, till you get 
it to your mind, but do not put on any fresh powder in the 
finishing for the last quarter of an hour, as it will give a finer 
surface. 

A Good Developer. — Mr Carey Lea recommends the fol- 
lowing : — Dissolve lo grains of Nelson's gelatine in an ounce 
of Beaufoy's acetic acid — that at lod. per lb. Make your new 
developer of the strength you are accustomed to use, of course 
without any acid ; and to each ounce of it add one drachm of 
the gelatinised acetic acid. You will be pleased with the 
result, and with its cleanliness and ease of preparation. This 
developer will be found to bring out the images with unusual 
vigour and brilliancy, and may be retained on the plate for a 
long time without ** fogging.'' Where from unavoidable diffi- 
culties under-exposure has arisen, this quality alone will render 
it invaluable. 

Sensitizing Paper. — Albumen, i oz. ; water, i oz. ; chloride 
of ammonia, lo grains. The paper is first floated on this and 
then ironed. It is then again floated on a bath of nitrate of 
silver, of the strength of 40 grains to 60 grains to an ounce of 
water. 

Purple Staining. — Take a moderate-sized cigar-box, with 
lid to fit close. Half-way up the box bore half a dozen holes 
large enough to admit thread each side. Strain tightly, from 
side to side, a half dozen pieces of thread ; fasten with wooden 
plugs. After the prints are "• toned," ** washed," and ^* fixed " 
in the usual way, dry them well, then lay them faces down on 
the thread. Underneath place a small saucer containing some 
carbonate of ammonia. Shut the lid of the box tightly. Expose 
the prints to the fumes from five to ten minutes, or longer if 
required. Examine occasionally until the desired effect is 
produced. 

Glass Globes for Magnifying Glasses. — A small piece of 
very fine glass sticking to the wet point of a steel needle 
is to be applied to the extreme bluish part of the flame of a 
lamp; (a spirit lamp is best;) being there melted and run 



PHOTOGRAPHY. 



219 



into a little round drop, it is to be removed, upon which it 
instantly ceases to be fluid ; folding then a thin plate of brass, 
and making very small, smooth perforations, so as not to leave 
any roughness on the surface, fit the spherule between the 
plates against the apertures. The same may be inserted in 
brass or ivory tubes for the photo-micro objects. 

Freezing Mixtures. — The following table of frigerific mix- 
tures, without ice, may be useful to many photographers in hot 
climates or our own country, to keep cool their baths or other 
chemicals by immersing their bottles, &c. : — 



Mixtures. 



Common salt... 
Nitrate potass. 
Aqua 



5 parts. 



Muriate ammonia. 

Nitrate potass 

Sulph. soda 

Aqua 



5 parts. 
S » 
8 „ 
16 ., 



Nitrate ammonia. 
Aqua 



I part. 
I It 



Nitrate ammonia. 

Carb. soda 

Aqua 



T part. 



Sulph. soda 

Dilute nit. acid. 



3 parts. 
2 



Sulph. soda 

Muriate ammonia. 

Nitrate potass 

Dilute nit. acid 



6 parts. 

4 M 

2 n 
4 M 



Sulph. soda 

Nitrate ammonia. 
Dilute nit. acid... 



6 parts. 
S n 

4 M 



Phosphate soda. 
Dilute nit. acid. 



9 parts. 

4 M 



Phosphate soda... 
Nitrate ammonia 
Dilute nit. acid... 



9 parts. 
6 „ 



Sulph. soda... 
Muriatic acid. 



8 parts. 

5 M 



Sulph. soda 

Dilute sulph. acid. 



5 parts. 
4 »» 



Thermometer Sinks. 



From + 50° to + 10° 



From + 50° to + 4° 



From + 50° to + 4= 



From + 


50- 


to — 


7° 


From + 


50° 


to — 


3° 


From + 


50° 


to — 


-10° 


From + 


50" 


to — 


■14° 


From + 


50° 


to — 


-12° 


From + 


50° 


to — 


•21° 


From 


+ 5o«> to 


0° 



From + 50° to + 3' 



Deg. of Cold 
produced. 



40 



46 



46 



57 



53 



60 



64 



62 



71 



50 



47 



If these are mixed at a warm.er temperature than that expressed 
in the table, the effects will be proportionately greater ; thus, 



220 



PHOTOGRAPHY. 



if the most powerful of these mixtures be made when the air 
is 4- 35°, it will sink the thermometer to 4- 2°. 

Plate-Holder. — In most plate-holders the glass is fixed 
with screws, which take some time to adjust. In this little 

instrument the ad- 
" ^J^-S -^ 



justment is mstan- 
taneous, besides the 
advantage of more 
accurately fitting the 
edges of the glass, 
and thereby lessen- 
ing the chance of 
breaking. It can 
also be used as a 
holder for exhibiting 
a portrait before dry. 
It is easily made, and 
amateur photograph- 
ers will find it of 
service. 

H, H, handles ; 
S, S, screws allowing 
the wood W, W, to 
form themselves pa- 
rallel by the pressure of the glass edges ; H, H, holes in the 
lathe ; P, pin ; F, fixed pin. 

Magic Lantern Photography. — Photographs may be pro- 
duced with a camera made in the following way : — A is an 
ordinary ^-plate lens, B the focusing screen, C a slide for 

holding negative. It 
will be observed from 
this sketch that trans- 
parencies may be pro- 
duced from negatives 
of the same size, or 
larger or smaller. 
While being used it may be tilted so as to allow the light of 
the sky to pass through the negative, or it may be used hori- 
zontally with a white screen to reflect light through the negative. 
The chemicals are the same as are used for negatives. Care 





PHO TO GRAPH V. 22 1 



must be taken that the silver bath and developer are sufficiently 
supplied with acid to prevent the slightest appearance of fog- 
ging. Or you may print from the negative by contact on glass 
or mica by the coUodio-chloride process, which gives very fine 
results. 

Black for Retouching Photos. — Indian ink consists of the 
charcoal of fish bones, or a vegetable substance, mixed with 
isinglass size, and probably honey or sugar to prevent its 
cracking. A substance much of the same nature, and appli- 
cable to tinting those enlargements denoted black and white, 
may be made thus : — Take 3 oz. of isinglass, form it into a 
size by gentle heat in double its weight of water ; then take 
half an ounce of Spanish liquorice, dissolve it also in double its 
weight of water, and grind it up with half an ounce of fine 
ivory black ; add this to the size while hot, and stir well 
together till thoroughly incorporated ; finally evaporate away 
the water, and cast the remaining composition into leaden or 
other greased moulds. The colour of this composition will be 
equal to the finest Indian ink j the liquorice will render it easily 
dissolvable on rubbing up, and prevent its cracking or peeling 
from the ground on which it is laid. 

Retouching. — Many photographs need to be retouched. 
Retouching is undoubtedly more practised on the Continent 
than it is in this country, and is occasionally used in the whole 
of the three possible forms : — Retouching on the model, such 
as strengthening eyebrows, deepening eyelashes with coloured 
*^ cosmetic,^' or the use of violet powder to red hair ; retouching 
the negative with pigment or blacklead pencil ; and retouching 
the print with a suitable water-colour. The darkening of eye- 
brows or eyelashes merely for securing an improved effect in 
the portrait is of course unjustifiable, inasmuch as it would alter 
nature and spoil the likeness, unless the sitters are in the habit 
of defacing nature by appliances of powder, paint, and dyes. 
The use of violet powder to modify the effect of red hair re- 
quires great skill not to produce an unnatural effect, but it is 
at times useful and effective. Retouching the negative requirse 
much skill to produce a good effect, but if done with judgment 
and skill is very valuable. It is effected with a lead pencil, 
to soften harsh lines in the face, and strengthen the detail in a 
few shadows. It in nowise interferes with the truth of nature. 



222 PHOTOGRAPHY. 



but modifies and ameliorates the inherent defects of photo- 
graphy, or of the photographic negative. In retouching a 
print, the great aim should be to do the least possible to effect 
the end in view, and especially to let the addition be in strict 
harmony with the peculiar characteristics of the photograph. 
For instance, any attempt to stipple upon a face in a formal 
way will generally issue in the necessity of covering the whole 
face with such stippling or hatching ; whilst a few skilful 
touches imitating the quality of texture or kind of detail in the 
print might have produced a really better and more pleasing 
result with one-tenth of the laboun 

Composition Pictures. — In the Exhibition of 1871, many 
photographs that were much admired were, in fact, simply 
*' compositions " from several negatives. Composition pictures 
— says Mr E. Dunmore, the well-known amateur photographer 
— are certainly the most daring attempts to burst the bounds 
of what is considered the limits of a process, and are attempts 
worthy of imitation by all. Light and shadow are our sheet 
anchors. A clever arrangement of the chiaroscuro, and a few 
touches, will make a picture, when myriads of touches and bad 
lighting will make a photograph the derision of every one who 
knows anything about art, perfect, perhaps, in its chemical 
aspect, but horrible in its pictorial one. When we see a beau- 
tiful result, we are apt to overlook the time, care, skill, energy, 
and battling with almost insuperable difficulties necessary to its 
production. The result is all we know, if it be good or bad. 
If good, no one can imitate it without undergoing the same 
ordeal to procure the negatives. 

Reproducing Negatives. — When it is desired to duplicate 
a negative, the following plan is to be adopted : — Spread on a 
glass the same size as the negative a mixture of bichromate 
solution, gum, and honey, to expose under the negative, and, 
after exposure, dust over with a pigment, which adheres to the 
unexposed parts, and forms a negative. This is to be washed 
with a mixture of alcohol and glacial acetic acid, which removes 
the bichromate without dissolving off the gum. Negatives 
obtained in this way are reversed, and give reversed positives. 
They are useful for photolithographic transfers. Instead of 
dusting the exposed plate with pigment, enamel powder may 
be used and the plate may then be burned in, and a negative 



PHOTOGRAPHY. 223 



of absolute permanence be obtained. (It seems doubtful if 
such a burned-in negative could have the fulness of detail of a 
collodion negative, from the tendency of colours to run a little 
when fused.) 

To Photograph Drawings, Manuscripts, &c. — The usual 
method is to copy them by reflected light, but Professor Fowler 
adopts the following : — The paper suitable is very thin, homo- 
geneous in texture, and machine-ruled or lined in the pulp or 
mass of the paper itself. Upon these lines the manuscript is 
carefully and boldly written, and so that not a single stroke is 
wanting. As soon as the page is complete, and the ink quite 
dry, make the paper transparent with a mixture of olive 
oil and turpentine, applied by means of a fine sponge to the 
back. The sheets are then hung up to dry. To obtain a 
negative of the manuscript, use dry tannin plates, and print by 
contact. In the printing-frame place first a clean flat glass ; 
upon this lay the manuscript, the back in contact with the 
glass ; and, last of all, press the tannin plate into close apposi- 
tion with the writing of the manuscript. The door is then 
closed. This operation is performed, of course, in the dark 
room. The front of the printing-frame is covered with a thin 
board, slate, or tin plate ; and having brought it in this condi- 
tion into the light, the board is removed from the front, and the 
manuscript is exposed for a few seconds. Replace the board, 
and carry the printing-frame back into the dark room. Here 
the negative is developed with pyrogallic acid and silver, and 
then fixed. The parts beneath the ink-marks are naturally 
transparent, whilst all the rest is uniformly opaque to the rays 
of light. This opacity is much more dense and uniform than 
that which is obtained by copying by means of reflected light. 
After washing, the plate is dried and varnished. A dozen 
similar negatives are soon taken in this way ; and it is then an 
easy task to print several hundred facsimile copies of the manu- 
script or drawing. 

Photographic Prints on Linen and Cotton. — Handker- 
chiefs, &c., are often ornamented with photographs, and, as a 
matter of curiosity, it may be as well to describe the process. 
The linen or cotton cloth is first freed from its ^^ dressing," and 
then coated with the following preparation : — Distilled water, 
125 cubic centimetres ; chloride of ammonium, i gramme ; the 



224 



PHOTOGRAPHY. 



white of one ^%g. The surface of the fabric is allowed to 
remain for five minutes in contact with the albumen mixture, 
then dried, and afterwards rendered sensitive by floating it on 
a ten per cent, solution of nitrate of silver. The latter opera- 
tion takes five or six minutes, and requires to be conducted 
with great care, as spots will inevitably occur in places where 
the silver solution touches an unalbumenized portion of the 
fabric. The printing should take place on the same day as the 
sensitizing, the remaining operations being proceeded with in 
the ordinary manner. Photographs produced by this method 
are very permanent, and may be washed with soap without 
sustaining injury. 

Design for a Photograpliic Studio. — Here we have the 
ground-plan of a photographic studio which has been found very 
effective. It is of what has been called the tunnel class, but 
differs from the kind recommended in the photographic journals 
in the larger amount of light it admits. Indeed it is probable 



4^ _7-.^0 




that, in an open situation, too much light would find its way 
to the sitter, and some would therefore have to be shut off; 
but of two evils, too much and too little light, the former is 
certainly the smaller, and is moreover advantageous, inasmuch 
as when decreased the shut out portion serves as a kind of 
reserve force for dull weather. It is based upon a design of 
admitted excellence, but the proportions differ considerably, so 
as to fit it for the use of amateur photographers. 



PHOTOGRAPHY, 



225 



Dark Box for Field-work. — When set up for work, the 
dimensions of the box herewith described are : — Length, 18 in.; 
width, 14 in. ; height, 13 in. ; outside measure when packed, 
5^ in. thick, or about the size of a soldier's knapsack. It is 
made of very thin 
deal covered with 
oil-cloth, and has 
round each corner 
pieces of sheet- 
copper riveted. 
At each corner, 
also, inside, there 
is a light ash up- 
right, hinged by 
passing a screw 
through the long- 
est side of the box, 
and riveting it in 
the upright, which 
can then fold down 
between the edges 
of the sides, top 
and bottom. There 
are three thick- 
nesses of black 
calico tacked, and 
in the top of the 
box there is a lid 
of sufficient size 
through which the 
bottles of chemi- 
cals, &:c., are 
handed. To set 
up the box for 
working it is fas- 
tened on its tripod 
stand, the screw- 
bolt of which, by 
a simple contrivance, slips into a groove in the box, and the 
straps which go quite round being undone, the lid is raised ; 
and the top being supported with one hand, the uprights are 




226 



PHOTOGRAPHY. 



lifted with the other, and entering into small blocks in the top, 
stretch the calico sides, and the whole thing is quite firm. In 
-the side of the calico, next the operator, there are sleeves 
through which he passes his hands to enable him to see what 
he is about. There is a large plate of yellow glass in the lid, 
and when his eyes are shaded he can see perfectly. The shade 
is made of stiff oil-cloth covered with black velvet ; it has 
pieces of sheet-iron riveted on to it at right angles, which slip 
into grooves in the lid. Anything to cover the head would do. 
as well, but the other plan is the most convenient to admit 
light into the box. There is a yellow-glass window in the side 
farthest from the operator, made by glueing a light wooden 
frame to the calico, the glass resting in a rabbet, and having a 

metal frame screwed over 
it. There is another 
small light in the lid 
which can be shut out by 
a revolving metal cover 
from the inside ; but it 
is only needed in a very 
dull light. In the floor 
of the box there is a 
yellow glass, so that in 
developing it can be seen 
when all the half tones 
are out by looking through 
the negative, a point of 
great importance. The 
bath is sunk through an 
opening in a bag, also the dark slide when done with. These 
bags have strong wire frames at top to prevent their slipping 
through the openings. Keep the bath always covered. The 
holes in the floor of the box have sheet-iron frames riveted 
over them to support the wood. The water-can is placed on 
the top, and the water is conducted on to the plate by an 
elastic tube, a patent shp cutting off the stream. The waste 
water from the dish is carried off by a tube passing through the 
bag in which the bath is placed. There is a wooden rack for 
bottles which contains everything for a long day's work, includ- 
ing chemicals for extra developing and fixing solutions, and 
bottle of bath solution for filHng up ; the gutta percha or glass 




PHOTOGRAPHY. 



227 



bath is made water-tight by a strap of -wide hoop-iron passing 
under it, and the ends being turned up the clamp catches them 
and presses the piece of wood and the indiarubber down on the 
top of the bath. When the box is packed for traveUing, the 
bath hes inside the tin water-tray or dish ; and it rests on the 
dark sHde. The bottle-rack and the water-can fill up the re- 
maining space ; the cleaning cloths keeping all snug. The 
plate-box hooks on the lid, protecting the yellow glass ; it will 
hold six plates, either half plates (6^ x 4|), or 4 x 5 plates ; 
they rest at two corners in grooves, and at the other corners 
on movable slips of wood, so that both sizes can be carried 
together, and cannot possibly get rubbed ; of course the smaller 
plates must be the upper ones. The folding tripod-stand is 
fastened to the top above the plate-box. Carry the pack like a 
knapsack, and you can go six 
or eight miles without fatigue ; A 

the weight is only about 20 lbs. 

Dark Tent. — Mr Wilson, of 
Aberdeen, recommends the fol- 
lowing plan : — The tent is 
composed of a light tripod of the 

usual height for the framework, and a covering of three folds 
of twilled calico, two black and one yellow. The cloth is first 
cut into lengths, about a foot more than the length of the tripod 
frame,then folded from B 

opposite corners, so 
that each piece may 
be cut along the dia- 
gonal of the parallelo- 
gram into two triangles 
A, which are after- 
wards sewn together 
so as to form, when 
laid flat on the floor, 
about three - quarters 
of a circle B. The 
edges are cut evenly 
round, and bound with tape, and when a square hole has been 
cut out of the two outer folds of black calico and two folds of 
yellow cotton to act as a window have been substituted, the tent 





228 



MUSICAL INSTRUMENTS. 



is complete. It can be pitched in half a minute by stretching out 
the tripod, until the legs are about three feet apart ; and when 
a few stones, pieces of wood, or anything handy, are placed 
round the bottom inside, it is ready for the bath and bottles. 



Portable Photographic Tent. — The roof is made of four 
pieces of timber 4 feet long and about f in. square, which are 
hinged to a circular piece of wood about 4 in. in diameter, in 
such a way as to admit of their shutting up like an umbrella. 
To each of these " rafters '' is nailed double calico, black lined 
with yellow. The eave overhangs about 3 in., on the inside of 
which are stitched strong hooks about 6 in. asunder, on which 
are hung the sides or walls of the tent. The legs are the same 



size as the rafters, 4 



feet long and f 



m. 



square. They are 



hinged to the inside of the rafters, and can fold in when shut 
up. Each leg is connected by a strong galvanized wire which 
hooks into- eyes (those used for stair rods will answer) close 
under the eave. Four strong cords from the top pass down 
each angle, through a couple of eyes, on to the ground, where 
they are secured by iron pins, thus making the whole perfectly 
steady. The sides are also black lined with yellow, and for 
convenience are divided into two parts 4 feet 3 in. wide, and long 
enough to allow an overlap of i foot at each joining. The 

door is made by un- 



fic. 




hooking three or four 
back 
and 



folding 



eyes, 

the curtain, 
hooking it on some 
of the inside hooks. 
Thus a perfect pho- 
tographic tent is 
made, which might 
be serviceable for 
several other pur- 
poses. 

iEolian Harp. — 

In the first place, a 
box must be made 

of twelve-cut board ; the length to be the width of the window; 

the box 6 in. deep, and from 8 in. to 1 2 in. in width, as shown 



MUSICAL INSTRUMENTS. 



229 



fig. I. A board must next be cut to fit the top of the box, with 
two openings A for sound, and be glued down. Take two 
pieces, as B, and gkie across, as shown in C ; these are to act 
as bridges for the strings. 

The strings are next to be placed across from one end to the 
other, passing over the top of the sounding-board, and resting 
on the two bridges ; the strings must be fastened by placing 
nails at one end to attach them, and screws at the other, the 
screws to be used 
so as to slacken 
and tighten as re- 
quired. Over these 
strings must be 
placed another 
piece, as A, with- 
out the incisions ; 
this is to rest on 
four small pegs, 3 
in. in length, placed 
at each corner. 
The window is then 
to be shut down 
on the top of this 
board, as in fig. 2, 
when the wind will 
pass through the 
strings, causing a 
most dehghtful 
harmony, especi- 
ally if a door or 
window in an op- 
posite part of the 
apartment be left 
open to cause an 
extra draught or 

current of air. The strings must be of small catgut, and must 
not be made too tight, or they may be stretched simply between 
two thin boards, about i in. or i^ in. apart, and made to fit 
the window. 

Another method. — The annexed sketches will explain : — ^ 
I. Top, 2 ft. 6 in. long, 5 in. wide, \ in. thick. 2. Bottom, 




230 



MUSICAL INSTRUMENTS, 



the same length, &c., as top, with two bits of wood aa^ 2 in. 
by 5 in. long, \ in, thick at each end, bb two bridges for the 
strings to rest on. The strings must not be tightened too 
much, but be regulated so as to be moved by the wind ; cc four 
screws to hold the box firm. The strings must be in the centre 
of the opening 0, You must obtain four catgut strings, two of 

the smallest size, 
nc.l. to put in the front 

side, that is the 
side whichthe wind 
first acts on, and 
the other two at 
the back. The four 
strings are fastened 
to the four holes at 
each end, as seen 
in fig. 2, and the 
top must be plain, 
with two holes at 
each end to screw to the bottom. When you wish to hear it 
play, fix it under the bottom sash of the window, taking care 
to put two pegs in the top to keep it from falUng. One made 
on the above plan played for six or seven years. 




FIC. 2. THE BOTTOM 
-2,2 



3 



fOM- 



-z , 'e- > 



■*N 


Znnr^— I*^.nvCKEa 








„ /" 


1 





Home-made Violins. — The more simple the form of the 
instrument the better will be the tone. The backs and sides 

of the Cremona 
violins were made 
of maple, and the 
bellies of pine wood 
well seasoned and 
dry. A plain deal 
box, with a violin 
neck glued to one 
of its ends, and fitted up with strings, bridge, &c., will be found 
far superior in point of tone to the ordinary run of violins. The 
back and belly are of soft pine wood (the grain very strong and 
equidistant) 14 in. in length ; width at bottom end 8^ in. ; 
width at top end 6 in. Of course the back and belly are made 
of two parts each, glued straight up the middle, and the thick- 
ness of each is i-5th of an inch in the middle (where the pieces 




MUSICAL INSTRUMENTS. 231 

are joined together), diminishing gradually right and left to 
I- 1 2th of an inch at the edges ; the depth of sides is 2 in., and 
the sound-holes are straight instead of being curved like an f. 
The neck and pegs are the same as other violins. If the 
instrument is to be varnished, the best varnish is shellac, dis- 
solved in spirits of wine. Any druggist will give it the proper 
stain. It does not signify what the colour is. The wood must 
not be stained before varnishing, as it will close up the pores, 
and so prevent a free and energetic vibration. The prefixed is 
a rough sketch of the home-made violin ; the dotted lines show 
the blocks in the inside for strengthening the instrument. Its 
internal capacity is greater than ordinary violins. The young 
musician, who wants an eloquent violin of the ordinary shape, 
will find full directions for striking out and making entirely in 
Otto's " Treatise on the Violin." 

The tone of a violin depends chiefly upon the form, size, 
thickness, and quality of the wood. The size of the body of a 
violin is about 14 in. long, 4| in. wide across the ^^ waist,'' or 
narrowest, and ^\ in. over the widest part of the back and 
belly. If the length, 14 in., be divided into 72 parts, it will 
form a convenient scale for measurement, and will accordingly 
be so made use of in this short account. 

The form, taking the violin as seen flatways, is best obtained 
from some violin of good pattern. But as power and brilliancy 
of tone are. in a great degree, due to the reflection of the vibra- 
tions (passing from the bow down the bridge and sound-post 
into the body of the violin), from the ribs as the containing 
boundary', back to the centre of the body (a fact not noticed 
by Otto or others), the form of the sides or ribs is a matter of 
some consequence. That a square violin reflects these vibra- 
tions only from side to side and end to end, and does not con- 
centrate, or focus them anywhere, must be obvious. And that 
such a form has power, is due only to its greater capacity, it 
being well known that large violins are most powerful in tone, 
and, therefore, in most request with skilled concert-players. 
As to the form taken, as the violin is seen sideways, it should 
be even more particularly adapted for the reflection of vibrations 
noticed, and is evidently so in all good instruments. The 
section of the back and belly of these, taken at the narrowest 
part or waist, will be found (outwards) concave near the side 
and convex in the centre, and this plan prevails more or less 



232 



MUSICAL INSTRUMENTS. 



all round the body. Old violins are, however, constantly seen 
with a wholly different model, convex in almost every part, 
high, and bulging towards the ribs ; but they have always a 
dull, hollow, tubby sound, which appears as if it could not get 
out, owing, doubtless, to the form inclining the reflection of 
vibration towards the ribs, instead of to the centre of the body. 
It would be difficult to give an exact section of back or belly 
of a violin, as it must depend upon the eye (bearing in mind 
the principle of reflection of sound) to model out these curved 
forms into flowing gradations from concave to convex. 

One mistake into which a beginner is likely to fall may here 
be pointed out. As the edges of the back and belly are a trifle 
thicker where they are glued to the sides, and as the outside is 

formed before hol- 
lowing out the inner, 
allowance must be 
made for this extra 
thickness, or the 
inner side of the 
back or belly will 
be concave where it 
should be convex, 
as at A, the proper 
form being as at B. 
Violin-making is 
an art requiring ex- 
perience and skill, and those wishing to succeed should, as in 
other arts, study what has been done by the most skilful ; and 
in this department Straduarius and Joseph Guanerius stand 
foremost, and have left the finest specimens of their particular 
skill, which should form the model for a good-toned violin. 

Dimenswfts of various parts of Violin. 

Sides or ribs, ^ of a part thick. 

Sides or ribs, 6\ parts wide, diminishing gradually to 6 parts 

at the neck. 
Side linings, | part thick, ij parts broad. 
Upper block, lo parts broad, 4 thick. 
Lower „ 8 „ ,,4 „ 




Corner 



8 



Belly under the bridge two-thirds of a part thick, diminishing 



MUSICAL INSTRUMENTS, 



233 



gradually to one-third at the edges. Back under the bridge 
one part thick, diminishing to half a part at the edges. The 
external edges of back and belly should be left rather thicker 
for strength. Bass bar, an inside piece glued to the belly and 
standing under and supporting the left foot of the bridge, 
thirty-six parts long, one and one-fifth parts broad, two parts 
thick in the centre, diminishing to two-thirds of a part at each 
end. In fig. i, a half section, these parts are shown. 

Wood. — In good violins the back, ribs, and neck, with key- 
box, are made of a species of foreign sycamore or maple, called 
harewood, the belly and sound-post of Swiss deal : for the 
former, English sycamore is too soft ; maple would probably 
be the best English wood ; and the best substitute for Swiss 
would be Finland deal, selected free from turpentine, light in 
weight, and of fine and regular bate or grain, from a centre 
plank, which should show the grain on the edge as well as the 
surface. All wood used should be thoroughly seasoned. It is 
said that wood, if often baked for the purpose of more completely 
freeing it from turpentine, &c., a certain crispness in the tone 
may be thus acquired. It should have been stated that the 
small blocks are made of sallow, but deal may be used. 



^vl 



Tools. — In making this violin, it is necessary to have 20 or 
more small wooden cramps made of close-grained wood, like 
the sketch ; of beech 
or birch, 3 inches or 
more in length, i in. 
wide at each end, 
and half an inch 
thick, with a notch 
dd \\ in. long, to 
receive the edge of 
the violin, which we 

get tight by two thin wedges, i^ in. long, \ in. broad, and \ 
in. thick, entering one at each side, as at <:, the wedges being 
placed on the back and belly, but not on the ribs. If in the 
event of being often wanted, wire-tapped screws wormed into 
the ends of the cramps as shown might be used made of about 
No. 10, or i-ioth of an inch wire, and got tight against 
wooden hooks, as at r, b being the violin. In commencing, 
let the amateur first cramp the back to the sides, exactly where 




234 TAXIDERMY. 



it requires to be, with five or six cramps on each side ; then 
release one side, which will spring off sufficiently to be glued. 
When glued, nip close together with ten or twelve cramps. 
This done, release the other side, glue and cramp it in the 
same manner. Then set it to dry and harden for a day or two 
before repeating the same process with nothing on the belly. 
When thoroughly dry, scrape off any superfluous glue from the 
edges. If any crevices appear, trace a little hot thinish glue, 
with the small end of a skewer, round the edges, so as to 
smooth or fill up every crevice. 

Musical Vibration. — The tones of violins being so various, 
it is almost difficult to judge the difference, or best, from the 
various tastes of players. Some like a fine or firm tone, some 
a loud tone, some a hard, sharp, or leading tone, some a crisp 
or wiry tone. Each may be deemed best in the estimation of 
such a variety of advocates. A violin with back, belly, and 
sides, all of pine, is not likely, as a general rule, to produce a 
fine clear tone, save from the spontaneous harmonizing vibra- 
tions, perchance, of back and belly. It is impossible for any 
manufacturer of violins, however defined his rule for construc- 
tion may be, to produce two or more consecutive violins that 
will possess an equal number of free vibrations of back and 
belly (minus the sounding-post), that is to say, the backs and 
bellies of each violin would not be in union with each other in 
their vibrations ; nor equal in power, tone, or quality. No 
doubt, the finest-toned viohns would be those whose natural 
free vibrations of backs and bellies are in unison, or in octaves 
to each other. But such occurring by chance is a mere lottery. 
Even those whose spontaneous free vibrations closely harmo- 
nise together will have an especial superiority over others 
whose free vibrations class amongst the wide-spread intervals 
of discord. 

Preserving Skins. — Small skins may be preserved in the 
following manner. They are first cleaned and scraped ; they 
are then rubbed over with arsenical soap, prepared thus : — To 
four pounds of white curd soap add one pound of arsenic and 
one ounce of camphor ; cut the soap into thin slices, and dis- 
solve it in one pint of water. When melted, add the arsenic 
and camphor, stirring them well together, and boil again, until 
the substance of a thick paste is attained, and pour it into jars 



TAXIDERMY. 235 



while hot. When cold, tie it up carefully with bladder, and it 
will retain its qualities for years. 

Rabbit skins ^ and indeed any moderately small skins, may 
be made white and the coat preserved, by first taking a blunt 
knife and scraping the skin on a piece of circular wood, so as 
to get off as much of the flesh and fat as possible ; then make a 
solution of alum, salt, and water, four to one of alum, as much 
as the water will contain. Dissolve the alum in hot water, 
when cold immerse the . skin in it, and in about forty-eight 
hours the skins will be cured. Wash in a weak solution of 
soda and water, to carry off any fat that may remain. If for 
sheep, or other skins that are thicker, a longer time will be 
required. The skins should be pulled about before thoroughly 
dry to stretch them. This plan is a very fair one, but is, of 
course, not perfect. 

Bird-Stuffing. — First dissect your specimen. In dissecting^ 
three things only are necessary to ensure success, viz., a pen- 
knife, a hand not coarse and clumsy, and practice. In stuffing^ 
you require cotton, a needle and thread, a little stick, glass 
eyes, a solution of corrosive sublimate, and any kind of tem- 
porary box to hold the specimens. Wire is worse than useless, 
as it gives a stiff appearance to the object stuffed. A very 
small proportion of the skull-bone, say from the fore-part of 
the eye to the bill, is to be left in, part of the wing-bones, the 
jaw-bones, and half of the thigh-bones remain. Everything 
else — flesh, fat, eyes, bones, brain, and tendons — are all to be 
taken away. In taking off the skin from the body, it will 
be well to keep in mind that you must try to shove in lieu of 
pulling it, lest you stretch it. Throughout the whole operation, 
as fast as you detach the skin from the body, you must put 
cotton immediately betwixt the body and it ; this will prevent 
the plumage getting dirty. Let us now proceed to dissect 
a bird. Have close by you a little bottle of corrosive subli- 
mate, also a little stick, and a handful or two of cotton. Now 
fill the mouth and nostrils with cotton, and place it on your 
knee on its back, with its head pointed to your left shoulder. 
Take hold of the knife with your two first fingers and thumb, 
the edge upward ; you must not keep the point of the knife 
perpendicular to the body of the bird, because, were you to hold 
it so, you would cut the inner skin of the belly, and thus let the 



236 TAXIDERMY. 



bowels out. To avoid this, let your knife be parallel to the 
body, and then you can divide the outer skin with great ease. 
Begin on the belly below the breast-bone, and cut down the 
middle, quite to the vent. This done, put the bird in any con- 
venient position, and separate the skin from the body, till you 
get at the middle joint of the thigh. Cut it through, and do 
nothing more there at present, except introduce cotton all the 
way on that side, from the vent to the breast-bone. Do exactly 
the same on the opposite side. Now place the bird perpen- 
dicular, its breast resting on your knee, with its back towards 
you. Separate the skin from the body on each side of the vent, 
and never mind at present the part at the vent to the root of 
the tail. Bend the tail gently down to the back, and while 
your finger and thumb are keeping down the detached parts of 
the skin on each side of the vent, cut quite across and deep, 
until you see the backbone near the oil-gland at the root of the 
tail. Sever the backbone at the joint, and then you have all 
the root of the tail, together with the oil-gland, dissected from 
the body. Apply plenty of cotton. After this, by shoving 
and cutting, get the skin pushed up until you come to where 
the wing-joints join the body. Apply cotton, and then cut this 
joint through, and do the same at the other wing ; add cotton, 
and gently push the skin over the head, cut out the roots of the 
ears, and continue skinning till you reach the middle of the 
eye ; cut the membrane quite through, otherwise you would 
tear the orbit of the eye. After this nothing difficult inter- 
venes to prevent your arriving at the root of the bill ; when this 
is effected, cut away the body, leaving just a little bit of the 
skull ; clean well the jaw-bones, and touch the skull and cor- 
responding parts with the solution. Now all that remains to 
be removed is the flesh on the middle joints of the wings, one 
bone of the thighs, and the fleshy root of the tail. Fasten 
thread to the joints of each wing, and then tie them together, 
leaving exactly the same space betwixt them as your knowledge 
in anatomy informs you existed there when the bird was en- 
tire ; hold the skin open with your finger and thumb, and apply 
the solution to every part of the inside. Neglect the head and 
neck at present ; they will receive it afterwards. Now fill the 
body moderately with wool, to prevent the feathers on the belly 
from being injured. You must recollect that half of the thigh, 
or, in other words, one joint of the thigh bone, has been cut 



TAXIDERMY, 237 



away. As this bone never moved perpendicular to the body, 
but, on the contrary, in an oblique direction, as soon as it is 
cut off the remaining part of the thigh and leg, having nothing 
now to support them obliquely, must naturally fall to their per- 
pendicular. Hence the reason why the legs appear consider- 
ably too long. To correct this, take your needle and thread, 
fasten the ends round the bone inside, then push the skin just 
opposite to it, and then tack up the thigh under the wings with 
several strong stitches. This will shorten the thigh, and render 
it quite capable of supporting the body without the aid of wire. 
Now is the time to put in the cotton for an artificial body, 
by means of the little stick, and then sew up the orifice you 
originally made in the belly, beginning at the vent. Lastly, 
dip your stick into the solution, and put it down the throat 
three or four times, in order that every part may receive it. 
When the head and neck are filled with cotton quite to your 
liking, close the bill as in nature. Bring the feet together by 
a pin, and then run a thread through the knees, by which you 
may draw them to each other, as near as you may judge 
proper. Nothing now reiiiains to be added but the eyes ; 
adjust the orbit to them as in nature, and that requires no other 
fastener. After this, touch the bill, orbit, feet, and former oil- 
gland at the root of the tail with the solution, and then you 
have given to the bird everything necessary, except attitude and 
a proper degree of elasticity. Procure any common, ordi- 
nary box ; fill one end of it, about three-fourths up to the top, 
with cotton, forming a sloping plane. Make a moderate hol- 
low to receive it, and place the bird in its right position. If 
you wish to elevate the wings, do so, and support them with 
cotton. If you wish to have the tail expanded, reverse the 
order of the feathers, beginning from the two middle ones, and 
when dry place them in their true order, and the tail will pre- 
serve for ever the expansion you have given it. In three or 
four days the feet lose their natural elasticity, and the knees 
begin to stiffen. When you observe this, it is the time to give 
the legs any angle you wish, and to arrange the toes. When 
the bird, is quite dry, pull the thread out of the knees, and take 
away the needle, and all is done. 

Insects for Cases. — Living insects, of which you wish to 
make ^^ objects," are instantly killed by putting them into a jar 



238 PLANT'PRESER VI NG. 



of carbonic acid gas. This gives them no pain, and leaves 
them in the best state for mounting. As soon as they are 
dead, spread them in the shape desired, and fasten them down 
to the box with a corking-pin. 

Skeleton Leaves. — Skeleton leaves may be prepared as 
follows : — 

1. Steep the leaves in rain-water, in an open vessel, exposed 
to the air and sun. Water must occasionally be added to 
compensate the loss by evaporation. The leaves will soon 
putrefy, and then their membranes will begin to open ; now 
lay them on a clean white plate filled with clean water, and 
with gentle touches take off the external membranes, separating 
them cautiously near the middle rib. When there is an open- 
ing towards the latter, the whole membrane separates easily. 
The process requires a great deal of patience, as ample time 
must be given for the vegetable tissues to decay and separate. 

2. A more expeditious method is the following : — A table- 
spoonful of chloride of lime in a liquid state mixed with a quart 
of pure spring-water. The leaves or seed-vessels of plants 
must be soaked in Jhe mixture for about four hours, then taken 
out and well washed in a large basin filled with water ; after 
which they should be left to dry, with free exposure to light and 
air. Some of the larger species of forest leaves, or such as 
have strong ribs, will require to be left rather more than four 
hours in the hquid. 

3. Perhaps the most effectual way is — First dip the leaves 
in boiling water, and then immerse them in dilute sulphuric 
acid, containing from 10 to 30 per cent, of the acid, according 
to the delicacy or coarseness of the leaf-structure. In a day 
or two use a pretty stiff bristle brush to the leaves, adding drop 
by drop a little saturated solution of bichromate of potassium. 
When the operation seems complete, wash the leaves carefully 
in ammoniated water, and finish with a little weak hypochlorite 
of calcium or chlorine water. 

4. Dissolve 3 oz. of common washing-soda in a quart of boil- 
ing water, and add i^ oz. of fresh -slaked quicklime ; boil it ten 
minutes. Pour into a pitcher, and let it stand a short time till 
settled ; then pour the clear solution again into the pan, and 
let it boil. Add the leaves, and boil for say an hour, adding 
water to supply that evaporated. Take one of the leaves out 



PLANT-PRESERVING. 239 

into a dish of clean water, and rub it gently between finger arid 
thumb. If the outer covering will leave the mid-rib and veins, 
they will do ; if not, boil longer. Bleach thus : — One drachm 
of chloride of lime mixed in a pint of water, and allowed to 
settle ; pour off the clear liquid, and put in the leaves. Steep 
them till white — say about ten minutes. If they stay too long, 
they become brittle. Wash them in a dish of clean water, and 
dry in a book between blotting-paper. 

When the ^' skeletons " are obtained by either of the four 
processes given above, they may be plated by being dipped into 
a very weak solution of phosphorus in bisulphide of carbon, 
dried, placed in a neutral solution of nitrate of silver for fifteen 
minutes, dried again, and lastly covered with dead silver in a 
small electro-plating apparatus. An almost equally beautiful 
result is produced if the " skeletons ^^ are dipped into a clear 
boiUng saturated solution of iodide of lead. When dry, they 
appear as if frosted with gold. If cautiously painted with a 
very concentrated alcoholic solution of mauve, skeleton leaves 
present the appearance of a magnificent and delicate casting in 
bronze. It is best to prepare leaves of one kind only at a time, 
as the time it takes to strip them differs considerably. The 
preparation of skeleton leaves is a very delicate and wearisome 
process, and should only be attempted by those happily con- 
stituted persons who can keep their patience under repeated 
failures. 

Dried Flowers Preserved in their Natural Colours. — 

Provide a vessel with a movable cover, and having removed 
the cover from it, fix over it a piece of metallic gauze of mode- 
rate fineness, and replace the cover. Then take a quantity of 
sand sufficient to fill the vessel, and pass through a sieve into 
an iron pot, where it is heated, with the addition of a small 
quantity of stearine, carefully stirred, so as to thoroughly mix 
the ingredients. The quantity of stearine to be added is at the 
rate of half a lb. to 100 lbs. of sand. Care must be taken not 
to add too much, as it would sink to the bottom and injure the 
flowers. The vessel with its cover on, and the gauze beneath 
it, is then turned upside down, and the bottom being removed, 
the flowers to be operated upon are carefully placed on the 
gauze and the sand gently poured in, so as to cover the flowers 
entirely, the leaves being thus prevented from touching each 



240 AQUARIA. 



other. The vessel is then put in a hot place, where it is left 
for 48 hours. The flowers thus become dried, and they retain 
their natural colours. The vessel still remaining bottom up- 
wards, the lid is taken off, and the sand runs away through the 
gauze, leaving the flowers uninjured. 

To Stock a Fresh- Water AcLuarium. — There ought to be 
about three plants to every gallon of water, and two or three 
fishes, according to size, to every plant. Respecting the 

Fishes suitable for the aqua7'iicm we may make the following 
remarks : — 

Crusian or German Carp [Cyprinus curassius). — There are 
two kinds of them ; one is rather broader than the other. Its 
colour is gold-like, and is darker toward its tail. You ought 
not to have any, in a little aquarium, longer than two inches. 
Its back is bream-shaped, and it rises from the nape to a high 
arch along the line of the dorsal fin. It is a little subject to 
fungoid growths. It will live in dirty water, and is easily fed 
with bread crumbs ; but you must always be careful not to give 
it more than it can eat at once, because the bread on the bottom 
of the aquarium will render the water impure. 

The Roach (Cyprinus rutilus) is very common. — It will also 
live in dirty water, and is very fit for an aquarium, 

Prussian Carp {^Cyprinus carpis), — It is easily separated 
from C curassius^ through its olive-brown colour, its beard 
round its mouth, and its tail and fins are darker. It is not as 
broad, but rounder. 

Gold Carp {Cyprinus auratus), called so by Linnaeus, the 
celebrated Swedish naturalist. It originates from China, its 
colour is gold, has the shape of C. curassius. When it is 
young it is silverlike. It is nice to look at, but very dull, and 
difficult to tame. They sometimes get poorly, and are covered 
with a white mould ; then you must remove it to a shallow 
basin, put a little salt on its back, and it will soon rub the 
mould off. 

Minnow (Cyprinus Phoxinus), ought to be in every aquarium. 
An aquarium without minnows is no aquarium at all — it is a 
makeshift. With a shoal of minnows and a few Prussian carp, 
an aquarium may be considered fairly stocked, because there is 
really something to look at, something to amuse, and something 
to instruct. They are very sharp and amusing, always on the 



AQUARIA. 241 



move ; but it is very strange that they hve in an aquarium, 
because you never find them in other than quite clean water 
in their wild state. Their lower parts have a red colour during 
the summer-time, but fright will make them assume a pale 
fawn colour. The back and the top of the head have a dark 
olive-green colour. It is a little fish, but round. It will never 
grow longer than three to four inches. You ought never to 
have any longer than two inches in a small tank. It is very 
easy to tame ; you can soon teach it to eat out of your hand. 

The Bleak {Cyprinus alburnus) is also a fitting fish for a 
tank, especially if you pick small specimens. It is active in its 
movements, has a white, silverlike colour, and is continually 
on the move. 

Perch {Cyprinus fluviatilis). — You must pick very small 
specimens. It is a very handsome fish, but must have quite 
clean water, and can consequently not live long in an 
aquarium. 

Stickleback (Gasterosteus), — Should never be put into an 
aquarium with other small fishes. They are greedy and un- 
easy, and scarcely ever let the other fishes alone, often killing 
several. They must therefore be kept in a tank by themselves, 
or where there are only large fishes. They are, however, very 
interesting. Dr Lankaster, speaking of this fish, says : — " He 
has all the ways of other fishes, and many more besides. Look 
into your tank ; see, there is one larger than the rest ; he is 
clothed in a coat of mail like a knight of old, and it is resplen- 
dent with purple and gold. See how his eyes glisten, and with 
every movement present a new colour. He is a male fish, the 
king of your little shoal. He has important offices to perform. 
Presently, in the course of a few days, if you watch him, and 
are fortunate, you will see this wonderful little fish engaged in 
the most useful manner in building a nest. He first seizes 
hold of one little bit of weed, then of another, and carries them 
all to some safe corner, till at last his nest is built. Having 
done this, he gently allures his mate to his new-made home. 
Here she deposits her eggs, and having done this, resigns the 
care of them to our hero of the purple and gold, who watches 
over them with an anxiety that no other male in creation but 
the male stickleback seems to know. He fans and freshens 
the water with his fins, and at last, when the young are hatched, 
watches over their attempts at swimming with the greatest 

Q 



242 AQUARIA. 



anxiety. Nor is this habit confined to the fresh- water stickle- 
backs. A lady, writing to me from Aberdeen, and describing 
her aquavivarium, says, 'A fifteen-spined stickleback {Gas- 
terosteiis spinachia) constructed a nest on a piece of rock 
which was covered with a fine green seaweed, depositing the 
spawn first, then covering it with loose seaweed, and lacing all 
together with a long thread, composed, apparently, of some 
secretion. The fish afterwards, for about the space of three 
weeks, watched the nest, never leaving it at all save for the 
purpose of driving away the other fish when they approached 
too near. When a stick was introduced into the vicinity of the 
nest, the fish would fly open-mouthed to attack it, and would 
bite it with great apparent fury. At the expiration of the 
above-named time, the young fry made their appearance by 
hundreds, but I am sorry to say they soon disappeared, being 
devoured by the other fish, and caught by the tentacles of the 
sea-anemones. The mother-fish continued her attendance at 
the nest as long as any of the young fry were left/ '^ 

If you see your fishes go up to the surface of the water in 
your aquarium, you have too many fishes ; so you must either 
take away some, or put in some more plants. If you then find 
that the glass sides commence to be green, you are obliged to 
put in some snails or molluscs, which will in a short time clean 
the glass ; but if you put in too many, they will commence to 
eat the plants, and then you have to remove some of them, 
especially LinncBus stagnalis^ because that one likes the plants 
better than the green moss on the glass. The best wood of 
which to construct an aquarium is East India teak. It is 
generally very evenly grained, easily cleaned up for polishing, 
and, all things considered, it seems the most suitable. It may 
be obtained at shipbuilding establishments, or of coach-builders, 
at a little over the price of mahogany. 

The Size. — For a small room, one to hold ten or twelve 
gallons of water is a good size. Suppose we get a piece for 
the bottom 2 ft. long by 14 in. broad, to finish i in. clear in 
thickness, and 4 ft. 4 in. to finish i| in. square for the pillars. 
We yet require a piece for the top frame 6 ft. 4 in. long, 2 J 
in. by \ in. thick. This is all the timber required for the 
tank. After plani^ig up the bottom and squaring the sides 
and ends, run a cutting guage round it if in. from the outside. 
This is the outside of the glass ; then again a \ in. within, to 



AQUARIA. 



243 



allow for the composition with which the glass is fixed. The 
groove must be a ^ in. or -^-^ in. deep. Next guage | in. from 
the edge for the distance the vase mould is worked back. The 
pillars to be planed up to i| in. square, and grooved on two 
sides in the centre -^ in. deep, allowing the same for compo- 
sition as in the bottom. This groove must be carefully filled 
up with a piece of deal before turning, and the length must be 
to show 1 2 in. of glass. Some care must be taken not to sink 
too much in turning, so as to get to the bottom of the groove. 
Leave a square i^ in. at the bottom, and | in. at the top. The 
pillar, to get the tank water-tight, ought to be tenoned into the 
bottom f in. deep. The best proportion of an aquarium is 
that the length ought to be double the width, and the height 
equal to the width ; as, for example, if the length be 2 feet, the 
height and width should be i foot. There ought to be neither 
paint nor varnish inside the aquarium ; they are injurious to 
the fish. The best time 




IRON 



of the year for making an 
aquarium is April, May, 
or the beginning of June, 
because the fish and in- 
sects are very still in the 
cold season, so that they 
are accustomed to the 
small space. 

A gentleman, with some 
years' experience of a 40- 

gallon aquarium, says that zinc or iron should be most strictly 
kept out of contact with the water ; iron is bad for the plants, 
and zinc is poisonous to the fish; the metal, being always im- 
pure, is dissolved more or less. You can try a varnish made by 
dissolving m.arine glue in wood naphtha made thin, and allowed 
to dry down to necessary consistence. This forms a capital 
varnish for the joints of aquarium over the lead cement. The 
varnish should be laid on thin for the fi.rst coat, as it then runs 
into small crevices ; each coat to stand a day. All lac var- 
nishes are attacked by the ammonia in the water. Should it 
be impossible to empty the tank or take out pipe, you might 
try a brass tube just large enough to drop over iron and zinc 
pipe, an indiarubber ring at bottom coming just below edge of 
brass tube to exclude current of water setting up between the 



244 



AQUARIA. 



tubes ; or, perhaps better still, a piece of indiarubber tubing 
slipped over the iron and zinc pipe. Portland cement is also 
injurious to fish. Roman cement should be exclusively used 
for rock-work, which should be soaked in water for a month 
before being placed with the fish. 

Aquarium Fountain. — A table or aquarium fountain may 
be made thus : — The design is simple, requiring no piston, 
weights, or other mechanism ; it is, in fact, a '' syphon with an 
enlarged bend." The experiment was first tried with a pickle 





bottle and two bits of tube. The air must be sucked out till 
the water, rising through a out of the jug «r, begins to run down 
the tube b ; the fountain will then play till all the water in c is 
exhausted, or as in the second engraving (representing the 
actual fountain). A is a glass shade fitted air-tight into a tray 
of tin or other material ; ^ is a tube with a nozzle, having a 
hole about i - 1 6th of an inch ; a piece of glass tube drawn to 
a point will do very well ; the lower end should nearly touch 



AQUARIA. 



245 




the aquarium, or other reservoir ; ^ is a tube, the top of which 
should be nearly flush with the tray as shown ; say 6 in. may 
be metal or glass, 
the rest may be 
elastic, or any other 
tube, and may con- 
vey the waste water 
through the bottom 
of the aquarium, or 
over the top, or out 
of a window. The 
weight of the water 
in the longer arm 
of the syphon b 
produces a partial vacuum in A, the water consequently rises 
through a. 

1. In this plan the pipe conveying the 
water from the piston to the jet is india- 
rubber, fastened to a piece of brass tubing 
about i^ in. long on top of piston, the 
other end being fastened to the jet-pipe, 
as shown in present sketch. The run- 
ning of water is also shown. IT, india- 
rubber tube, connecting JP, jet-pipe, with 
top of piston. WP, waste-pipe, convey- 
ing the water from B down outside of 
jet-pipe to cylinder. It may be open or 
closed at top ; if closed, the cap must be 
drilled full of little holes. The water in 
B has to rise to top of this waste-pipe, 
thus keeping a good supply of water for 
fish. The tube WP may be hidden by 
artificial rocks. 

2. In this diagram, A is a porcelain 
or other basin, B and C are two glass 
globes connected by two tubes D and F, 
of which D commences near the top of 
the upper globe, and ends near the top 
of the lower one ; and F commences at 
L in the basin A, and ends near the bottom of the lower globe. 
The third tube E commences in the jet at J, and ends near the 




246 MISCELLANEOUS CHEMICAL PROCESSES 



bottom of the upper globe. G is a plug fastened by a string 
at K; H is a stopcock leading out of the lower globe to the 
outside of the aquarium; WW is water. This fountain is 
placed in the aquarium till the water is a little above the vessel 
A. When you wish it to play, pull out the plug G, and open 
the stopcock H ; the water then rushes in at G till it is nearly 
level with the top of the tube D, and then the plug G is re- 
placed, the stopcock H is closed, and the jet J, which must also 

have a stopcock, is 
opened ; the water 
then rushes down the 
tube F into the lower 
globe, the water forces 
the air up the tube D 
into the upper globe, 
and the compressed 
air forces the water 
in the upper globe 
through the tube E, 
and through the jet J. 
Then when the water 
in B is exhausted, 
shut up the jet, pull 
out the plug G, and 
open the stopcock H, 
&c. 



Spirit Blow-Pipes. 

— Two spirit blow- 
pipes, figs. I and 2, 
are described below : 
Fig. I has a boiler. A, 
made of copper, in 
the most suitable 
shape. It must be 
air - tight. B is a 
safety-valve, which is 
kept close by a spiral 
spring inside. The valve B must be made with a socket, the 
socket being brazed on top of boiler ; it must be made to screw 
off and on ; a pipe, D, must then be brazed in at the top, a stop- 




AND COMPOSITIONS. 



247 



cock, C, must be put on the pipe, and another pipe, Dl, must be 
connected on the end of stopcock, and brought a Httle more than 
half-way under the bottom of boiler. If required for making 
gasfitters' joints, a small round hole in the end G will answer 
best ; if for melting sheet-brass, the end made flat will do. It 
would be a good plan to get jets to screw on and ^ 
off. A socket should be brazed on the side, with ^^r^ ^-^-'^ 
a piece of iron tapped into it ; the piece of iron R 
should be tapped at both ends, and a socket with 
a thumbscrew made to screw on to it. A piece of round bar- 
iron or gas-pipe should be put for a slide F, and a piece of 
sheet iron should be put at the bottom for F to be fixed into, 
and for the lamp H to stand on. I is a regulator to turn the 
wick up and down. 

A vent-hole should p|| p|[B| FIC.2. 

be left in the top 
of lamp, the boiler 
should be filled up 
to within i inch of 
the top with methy- 
lated spirits, and 
the lamp may be 
filled with the same. 
Care must be taken 
to have everything 
sound, and an in- 
diarubber washer 
should be put on 
the under side of 
rim of safety-valve; 
the valve can be 
taken out to put 
spirits in. Stop- 
cocks can be got 
about I in. long. 

Fig. 2 is another 
style of blow-pipe. 
A frame of sheet iron is made similar to a pint pot, only the 
lower part of the front is cut away to make room to put the 
lamp H in, and to allow the flame to come out. A is the 
boiler, made of two pieces of copper, with both edges closed to 




248 MISCELLANEOUS CHEMICAL PROCESSES 

form a rim outside ; the boiler should be made to fit the frame, 
a safety-valve, B, should have a socket brazed in at the top of 
boiler ; the valve must be made to screw in and out. A spiral 
spring must be put to keep the valve closed ; a pipe, D, must 
be put in as near the top as possible ; a stopcock, C, must be 
put as near as it can be, so as to come above the frame that 
holds the lamp and boiler ; a pipe, Dl, must be put to conduct 
the gas down to the bottom, a little more than half-way under 
the boiler ; a lamp, H, must then be put under, leaving about 
an inch between the boiler and lamp. A small hole must be 
made in the back of the frame for the regulator I to come 
through; the pipe should terminate the same as in fig. i; a small 
ring should be put on the bottom of fig. 2 of the lamp to draw 
it out when required. Both boilers must be supplied by taking 
out the safety-valve, and nearly filled wdth methylated spirits. 

A Spirit Blow-pipe, made on either of the above plans, 
effects a considerable saving of spirits. On lighting the lamp, 
the cock can be turned off till the spirits are hot ; it can then 
be turned on, and the flame can be regulated as required. 

Spirit Blow-Pipe. — It is all copper, and cylindrical ; but 
shown in section with lid on. The pipe or tube, as will be 
_ seen, forms the handle, and is put in 

operation by igniting the spirits, which 
-^.^^ are up to the dotted lines, and extin- 

^>N guished by simply putting on the lid ; 
\\ it can be made to meet the require- 
---^/ ments of almost any class of artizan. 
=;=;^^__^ It is very simple, compact, easy to 
manage, and stands on its own bottom. 
By connecting another vessel for the regular supply of spirits, 
it can be kept going for any length of time, and by other simple 
arrangements the flame can be placed in any direction. 

Amateur's Gas Blow-Pipe. — This may be easily con- 
structed. All that is requisite is a common blow-pipe and a 
piece of brass tube about 3- 1 6ths of an inch in diameter. Bend 
the tube slightly at one end, and at the shoulder make a hole 
so that the small end of the blow-pipe may pass through into 
the larger tube, to come about flush with its end. Solder the 
joint to make it air-tight, and fasten pieces of vulcanized india- 
rubber tube of any convenient length to each of the other ends 



AND COMPOSITIONS. 



249 



of the brass tubes, and the instrument is complete. Let gas 
pass through the larger tube and ignite it ; now blow through 
the blow-pipe, and by regulating the gas-flame you can easily 
obtain any degree of heat you wish, as well as a very steady 
flame of any shape. 
Few who have 
once used it will 
willingly go back 
to the single tube 
or ordinary blow- 
pipe. The fine 
end of the blow- 
pipe should be 
about the centre of 
the larger or gas 
tube. 




Matches without Phosphorus. — The following mixtures 
will be found to answer satisfactorily : — i. Divide a solution 
of copper into two equal parts ; supersaturate one with am- 
monia and the other with hyposulphate of soda ; mix them 
together, and dry the precipitate, which will fall. Mix this 
with strong glue and a small quantity of powdered glass. 
Lucifers made with this mixture will ignite on any rough sur- 
face. 2. Take from four to six parts of chlorate of potash, 
and two parts each of bichromate of potash, and of oxide of 
iron or lead, and mix with three parts of strong glue. For an 
igniting surface, take from four to six parts of oxide of either 
iron, lead, or manganese, two parts of glass -powder, and from 
two to three parts of strong glue or gum. These 7natches will 
igitite only on the friction surface thus prepared. Another 
German chemist uses for the match-heads a mixture of chlorate 
of potash and a salt which he describes as a compound of 
hyposulphurous acid with soda, ammonia, and oxide and sub- 
oxide of copper. He forms this compound by dividing a solu- 
tion of copper into two equal parts, supersaturating one of them 
with ammonia, and the other with hyposulphate of soda ; then 
mixing the two solutions, and stirring the mixture well. A 
violet powder precipitates ; one part of it is to be mixed with 
two parts of the chlorate of potash, and a small quantity of 
pounded glass. Lucifers made in this way, however, will 



250 MISCELLANEOUS CHEMICAL PROCESSES 

ignite on any rough surface, even more easily than the common 
kind. 

Use of Alum in Iron Safes. — In fire-proof safes there is 
a certain space filled with powdered alum. When the heat 
reaches this, the water of crystallization is driven off, by which 
a great absorption of heat is produced, .and the temperature of 
the interior of the safe kept proportionately low. This is the 
principle of Milner's safe. 

Chlorate of Potash. — Mix 3 lbs. of common salt, 2 lbs. of 
manganese at 8d. or 9d., and 2 lbs. by weight of oil of vitriol, 
previously diluted with about 2 pints of water, and allowed to 
cool ; distil into a retort containing 6 oz. pearl ash, dissolved 
in 3 lbs. of water ; when the distillation is finished, evaporate 
the liquid in the receiver slowly in the dark. The chlorate 
will crystallize in flakes. Of course these quantities may be 
altered to suit the convenience of the operator. 

Spontaneous Combustion of Oil Rags. — When cotton waste 
or shavings are saturated with oil, a large surface is exposed 
to the action of the air ; and if the oil has the property of 
absorbing oxygen, it may absorb the gas so rapidly as to take 
fire. This is the way in which spontaneous combustion takes 
place. As petroleum naphtha does not absorb oxygen, it never 
takes fire by spontaneous combustion. 

Lubricating Composition. — Good lard, 16 oz. ; bees'-wax, 2 
oz. ; olive or sperm oil, 40 oz. ; flowers of sulphur, 8 oz. ; black- 
lead, 4 oz. (in powder, and free from grit) ; white soap, i oz. ; 
all of the best quality, and to be well incorporated. 

Crucibles of Lime. — In these experiments a clay crucible 
of somewhat larger capacity than the desired lime one is filled 
with common lampblack, compressing the same by stamping 
it well down. The centre is then cut out with a knife until a 
mere shell or lining of lampblack is left firmly adherent to the 
sides of the crucible, and about half an inch or less in thick- 
ness, according to the size of the crucible ; this lining is now 
well rubbed down with a thick glass rod until its surface takes 
a fine glaze or polish, and the whole cavity is then filled up 
with finely-powdered caustic lime, and pressed down as before, 
and a central cavity cut out as before ; or the lime-powder may 



AND COMPOSITIONS. 



251 



be at once rammed down round a central core of the dimen- 
sions of the intended Hme crucible. This lime lining is natu- 
rally rather soft before being placed in the furnace, but upon 
heating agglutinates, and forms a strong and compact crucible, 
which is prevented acting upon the outer one by the interposed 
thin lampblack layer, and at the end of the experiment gene- 
rally turns out as solid and compact as those made in the lathe. 
Experiments made with such crucibles, even up to dimensions 
containing several pounds of metal, have proved them extremely 
well suited for these operations, and doubtless similar crucibles 
could be made lined with magnesia or alumina as required. 
In some cases ordinary blacklead crucibles, lined with pow- 
dered Hme, magnesia, or alumina, might possibly be found to 
answer. 

Chemical Balance. — A thin piece of fir-wood, not thicker 
than a shilling, and a foot long, and 1 in. broad, is divided 
into twenty parts — that is, ten parts on each side of the middle; 
these are the prin- 
cipal divisions, and 
each of them is sub- 
divided into halves 
and quarters ; across 
the axis is fitted 
one of the smallest 
needles, and fixed to 
its place by sealing- 
wax. The fulcrum 
is a piece of brass, 
the middle of which 
lies fiat upon the table. The two ends are bent at right angles, 
so as to stand upright, and are ground flat upon a hone. They 
stand above the surface of the table only i-5th of an inch. This 
balance will weigh the minutest quantity, even the 1200th of a 
grain. A grain weight is placed on one division, and the object 
on the Qther ; the proportion of the two will indicate the weight 
of the latter. The other is on the same principle ; the scales 
are of ivory, from which a small bullet is suspended by a wire ; 
the process of weighing as in the former balance. 

Laughing Gas. — Laughing gas' (nitrous oxide) is prepared 
from nitrate of ammonia by heating it in a glass retort, or in a 




252 MISCELLANEOUS CHEMICAL PROCESSES 




clean dry Florence flask, with a bent glass tube attached. The 
stem of the retort or tube must dip into a pneumatic trough, 
on the shelf of which the jar to collect the gas is placed. A 
solution of 2 oz. of sulphate of iron in one gallon of water, 
warm, should be used in lieu of water, as it purifies the gas. 
On the application of heat, the gas passes over into the jar, 

driving, of course, 
the water out. An 
ordinary gas jar will 
do to collect the 
gas, in the mouth 
of which a cork, 
with a piece of 
glass tubing, with 
anindiarubber pipe 
attached, passed 
through it, is in- 
serted. A stopcock must be attached to the pipe to prevent 
the escape of gas till wanted. 

To inhale, — Place the tube in the mouth, empty the lungs of 
air, stop the nostrils with the fingers, and then inhale the gas, 
say for a few seconds. The effects vary with the constitution. 
Combative people should not take it, nor should it be adminis- 

£ tered to females. 

The source of heat 
must be withdrawn 
immediately any 
white fumes appear 
in the retort ; and 
care should be 
taken to control 
those under the in- 
fluence of this gas, 
as they are then 
utterly unable to 
do so themselves. 
The frequent use of 
nitrous oxide is not 
conducive to health. A, retort ; B, Florence flask ; C, pneu- 
matic trough ; D, gas jar. ^, spirit-lamp ; ^, stopcock ; c^ 
conducing pipe ; d^ shelf of strength. 




AND COMPOSITIONS. 



253 




Another mode of preparing. — An ordinary retort, purchasable 
at any glass-house, is shown at A. The stand for the retort is 
seen at B, with, C, a screw to fix the ring in which the retort 
rests; D is the spirit-lamp; E is a bottle containing water, into 
which the gas rises, having escaped at the mouth of the retort 
at /, and passes through the water in the trough F into the 
bottle E, in little bubbles, driving the water out of the bottle 
as the gas rises to the top ; GGGGG is a table of triangular 
form, supporting the trough F. Into the retort A must be 
placed some of the 
salt called nitrate of 
ammonia ; then set 
light to the spirit- 
lamp under the retort 
or Florence flask ; a 
gas will be given off 
which will pass down 
the tube of the retort, 
under the water, and 
thence rise into the 
bottle, forcing the 
water out as it rises. 
This process of collecting gas is called " collecting over water." 
When the bottle is perfectly empty of water, it is full of nitrous 
oxide — the gas required ; and in taking the bottle from the 
water, the stopper should be placed in before letting the mouth 
of the bottle come beyond the surface of the water, or else the 
gas will escape. As many bottles of gas as are required can be 
prepared in this manner. 

Laughing gas is now used as an anodyne by the dentists. 

Nitrate of Potash. — New Process. — It has been ascer- 
tained, by M. Condurie, that nitrate of potash may be formed 
from nitrate of soda, by a very simple process. This consists 
in mixing concentrated and equivalent solutions of nitrate of 
soda and chloride of barium, or sulphate of baryta, which pre- 
cipitates the sparingly soluble nitrate of bar}^ta : washing the 
latter and boiling it with sulphate of lead, which forms nitrate 
of lead and sulphate of baryta ; and boiling the nitrate of lead 
with sulphate of potash, which forms the required nitrate of 
potash, and reproduces the sulphate of lead. 




254 MISCELLANEOUS CHEMICAL PROCESSES 

To Clarify Impure Water. — The chemical agent to effect 
this object is a solution of the neutral sulphate of peroxide of 
iron (Fe^, O3, x 3 SO3), which is to be added, in a very diluted 
state, to the water intended to be operated upon. 

The proportion in which the solution of neutral sulphate is 
to be added to the water, for the purpose of the invention, 
must be determined by the amount of the impurity contained 
therein. The suitable proportions must therefore be ascertained, 
by careful experiment carried on from time to time, if it should 
be found that the impurity of the water varies. The addition of 
more or less of the neutral sulphate will not materially affect 
the process beyond the evident fact, that too dilute a solution 
of the salt would probably either leave some of the impurities 
in the water, or the purifying process would be more costly 
than would be necessary for the complete success of the 
process. 

The water to be purified may be run into a tank or reser- 
voir, and the solution of neutral sulphate added thereto as it 
runs in, so that the solution may be well mixed with the water 
to be purified. A short time after the neutral sulphate is added 
to the impure water it becomes decomposed, and forms, with 
some of the impurities contained in the water, a basic salt, 
which is insoluble in water. The solid and insoluble particles 
of this new salt are precipitated, and, together with the im- 
purities contained in the water, form a sedimentary deposit, 
from which the purified water may be allowed to run off, leav- 
ing behind the sedimentary deposit in the tank or reservoir. 
A repetition of this precipitation process on other bodies of 
water which may be run into the same tank or reservoir will 
cause additional deposits, which, when they have been allowed 
to accumulate to a sufficient depth in the reservoir, may be 
collected, and removed from the reservoir from time to time. 
This process has been patented by Mr Edward Newton. 

Refining Olive Oil. — The best olive oil, in its crude state, 
possesses that peculiar bland flavour which fits it for the table, 
and which appears to arise principally from the quantity of 
mucilage and water, either held in solution, or mechanically 
mixed with it. By keeping one or two years in jars, a consi- 
derable portion of the mucilage and water subsides, which 
renders such oil not only cheaper, but better qualified for yield- 



AND COMPOSITIONS. 255 

ing a greater proportion of pure oil than that which is recently 
expressed from the fruit. Two or three gallons skimmed from 
the surface of a large jar that has remained at rest for twelve 
months or upwards is preferable to any succeeding portion from 
the same jar, and may be considered the cream of the oil. 
Having procured good oil in the first instance, put about one 
gallon into a cast-iron vessel capable of holding two gallons ; 
place it over a slow, clear fire, keeping a thermometer sus- 
pended in it; and when the temperature rises to 220"^, check 
the heat, never allowing it to exceed 230°, nor descend, below 
212, for one hour, by which time the whole of the water and 
acetic acid will be evaporated. The oil is then exposed to a 
temperature of 30° to 36° for two or three days (consequently 
winter is preferable for the preparation, as avoiding the trouble 
and expense of producing artificial cold). By this operation a 
considerable portion is congealed ; and while in this state, 
pour the whole on a muslin filter, to allow the fluid portion to 
run through ; the solid, when re-dissolved, may be used for 
common purposes. Lastly, the fluid portion may be filtered 
once or more through newly-prepared animal charcoal, grossly 
powdered, or rather broken, and placed on bibulous paper on 
a wire frame, within a funnel, by which operation rancidity 
(if any be present) is entirely removed, and the oil is rendered 
perfectly bright and colourless. 

Refining Lard Oil. — Bancroft's Process. — Stir the oil with 
a lye of caustic potash of the specific gravity of i*2. A suffi- 
cient quantity has been added when a portion begins to settle 
down at the bottom. After twenty-four hours the clear oil 
should be decanted from the soapy sediment and filtered. It 
may be bleached by using a saturated solution of hydrochloric 
acid with bichromate of potash. 

Petroleum Stove. — A neat and compact arrangement for 
burning mineral oils, as a substitute for gas, in small cooking- 
stoves, has recently been adopted in the United States. 
Although such stoves are not likely to come into use in this 
country for cooking purposes, they might be found convenient 
in chemical laboratories, where gas is not readily obtainable. 
The base of the stove is an open-work cast-iron pediment, 
standing on three feet, and holding a tin can, from the centre 
of which rises a wide wick, passing through a drum, which 



256 MISCELLANEOUS CHEMICAL PROCESSES 

serves as a base for a funnel-like chimney. The case of this 
chimney is of tin, lined throughout with fine brass gauze. At 
the bottom the chimney-case has openings on the sides for the 
admission of atmospheric air. The outer cylinder is of Russian 
sheet-iron, and is surmounted by a cast-iron ring, having 
upward projecting points to sustain the cooking utensil. These 
points elevate the vessel sufficiently to allow the heat from the 
flame to circulate above the top of the stove around the sides 
of the kettle. The can is filled with naphtha, benzine, kerosene, 
or petroleum, the chimney removed, and the wick lighted. 
The chimney is then replaced, and the stove is ready for 
operation. If the wick is kept down below the point where 
the flame would produce illumination, there will be no deposits 
of carbon on the vessel used for cooking, and the gauze, with 
the plentiful supply of oxygen through the chimney apertures, 
will yield intense heat. 

Sealing- Wax. — The following are the materials and pro- 
portions for making red and black sealing-wax : — 

For black — 

Venice turpentine ... 

Shellac 

Colophony 

Lampblack mixed to a paste with oil of turpen- 
tine, a sufficient quantity. 
For red — 

Venice turpentine ... 

Shellac 

Colophony 

Chinese vermillion 

Magnesia, moistened with oil of turpentine 
For the best red — 

Venice turpentine ... 

Shellac ... ... 

Cinnabar ... 

Carbonate of magnesia with oil of turpentine 

Any of these would also do for white sealing-wax, by substi- 
tuting flake white for the lampblack, vermillion, and cinnabar. 
Adding a small quantity of fine gum benzoin will give them an 
agreeable perfume. 

Lime Water is made by adding 2 oz. of slaked lime to i 
gallon of water, and shaking it wtU for a few minutes. After 
twelve hours the excess of lime will have subsided, and the 
lime water may be drawn off by means of a syphon as required. 



4i 


oz. 


9 


oz. 


4 


oz. 


2 


oz. 


4 


oz. 


I 


oz. 


li 


oz. 


li 


dr. 


4 


oz. 


7 


oz. 


4 


oz. 


14 


dr. 



AND COMPOSITIONS. 257 

Sugar, Use of Lime in Extracting. — Peligot long ago de- 
monstrated that, owing to the insoluble nature of the compound 
formed of lime with sugar, the former substance would be a 
most valuable agent in the manufacture of the latter. Peligot^s 
suggestion is now being carried out on a large scale in MM. 
Schrotter and Wellman's sugar-factory at Berlin. The molasses 
is mixed with the requisite quantity of hydrate of lime and 
alcohol in a large vat, and intimately stirred for more than 
half an hour. The lime compound of sugar which separates 
is then strained off, pressed, and washed with spirit. All the 
alcohol used in the process is afterwards recovered by distil- 
lation. The mud-like precipitate thus produced is mixed with 
water, and decomposed with a current of carbonic acid, which 
is effected in somewhat less than half an hour. The carbonate 
of hme is removed by filtration, and the clear liquid, contain- 
ing the sugar, evaporated, decolourized with animal charcoal, 
and crystallized in the usual manner. The sugar furnished by 
this method has a very clear appearance, and is perfectly crys- 
talline. It contains, according to polarization analysis, 66 per 
cent, of sugar, 12 per cent, of water, the remainder being 
uncrystallizable organic matter and salts. The yield, of course, 
varies with the richness and degree of concentration of the raw 
material ; on an average, 30 lbs. of sugar were obtained from 
100 lbs. of molasses. 

Prince Rupert's Drops. — The properties of unannealed 
glass are beautifully shown in these scientific toys. They are 
made by dropping melted glass into water, which takes a long 
oval form, tapering to a point at one end. While the body of 
these drops will bear a smart stroke from a hammer without 
fracturing, if a portion of the smaller end is snapped off^ the 
whole mass will be broken into an almost inpalpable powder 
with a violent shock. Professor Faraday used to illustrate the 
incompressibility of water by placing one of these drops in a 
phial of water, the concussion from the disruption of the drop 
shattering the glass bottle. Another interesting' experiment 
with the same toy is this : — In place of water, fill the phial 
with melted resin, and when this has solidified, nip off the end 
of the glass drop. The bottle is broken as before, and the 
mass of resin is deeply fissured throughout its length. The 
drop is found as a kernel, loosely aggregated together, but 

R 



258 MISCELLANEOUS CHEMICAL PROCESSES 

easily detached from the resin entire. When broken in pieces, 
the fragments will be seen to have the form of a cone on an 
hemispherical base, like some forms of hail. 

Printers* Ink. — A capital ink is made as follows : — Put 
linseed oil into an iron pot capable of holding at least two or 
three times the quantity introduced, heat it over a fire until a 
dense vapour arises from it ; then, having removed the pot 
from the fire, apply a lighted match, attached to the end of a 
stick, to the surface of the oil, v^^hen the vapour will inflame ; 
allow it to burn for half-an-hour or more, until on taking out a 
small quantity of the oil, it is found to be thick and tenacious ; 
the flame is then to be extinguished by putting a cover over the 
pot, and keeping tightly covered. To 6 quarts of oil, thus 
prepared, add gradually 6 lbs. of black resin, and dissolve 
it by the aid of heat, then add, in small quantities at a time, 
1 1 lbs. dry yellow soap, cut into slices, and effect the combina- 
tion by stirring and the application of heat ; this is the varnish 
of which the ink is to be made, and on the careful preparation 
of which the quality of the ink much depends ; this is to be 
miixed with i\ ounces of ground indigo, the same quantity of 
ground Prussian blue, 4 lbs. mineral lampblack, and 3^ lbs. of 
the best vegetable lampblack, and the whole ground together 
into a perfectly smooth and uniform paste. 

Ink of different colours is made by mixing the varnish with 
various dry pigments, such as vermilion, redlead, Indian red, 
chrome yellow, chrome red, verdigris, Prussian blue, &c. &c. 
These colours are ground up in the varnish with a stone and 
muller. 

In the above process there is considerable danger of the oil 
boiling over (which would be a serious affair), and wherever it 
is practicable, the best plan is to buy it of a good printing-mk 
manufacturer. 

To Restore Faded Ink. — Ink faded from age may be revived 
by damping the manuscript with very weak vinegar, and allow- 
ing it to remain damp for an hour or two. Then carefully 
wash the paper over with a solution of prussiate of potash. 
If the writing does not appear clear at once, expose the 
paper to the air for a few hours, keeping the whole slightly 
damp. 



AND COMPOSITIONS. 259 

Inks. — Black Ink. — Excellent kind of writing ink may be 
obtained by any of the following methods : — 

1. (Without galls), Logwood chips ^ lb. ; boil in three pints 
of water down to 2 pints, strain well, and let it cool ; then add 
2 5 grains of bichromate of potash. Stir well, add a little gum 
arabic and a few cloves. 

2. (The same in different proportions.) Take i lb. of 
logwood chips, and pour on a pint of boiling water ; let it 
stand until all the colour is extracted ; then strain it, and add 
to the solution about a thousandth-part of chromate of potash, 
or sufficient to make it the proper colour. This mixture does 
not require the addition of gum or anything else to give it con- 
sistency ; it will corrode steel pens, and is a fine permanent 
black. 

3. Take bruised Aleppo galls, 2 oz. ; green copperas, 3 drs, ; 
clean rain-water, i quart ; and best gum arabic, 3 drs. Mix 
in a bottle, and it will be fit for use. 

4. A fine Blue-black. — Take bruised Aleppo galls, 5^ oz.; 
bruised cloves, \ oz. ; sulphate of iron, i| oz.; sulphate of in- 
digo, in the form of a slightly acid paste (sulphindylate of 
potash .^), i^ oz. ; sulphuric acid, 35 minims ; ^^Z/ rain-water, 
40 oz. Macerate the galls and cloves in 20 oz. of the water 
for a week ; decant the liquor, and add to the residue of the 
solid ingredients 10 oz. of the water, with which continue the 
maceration for four days ; then decant as before, and repeat 
the maceration with the remaining 10 oz. of water for another 
period of four days. Mix now the whole of the liquors, re- 
covering from the galls all that can be obtained by squeezing 
them in a cloth, and afterwards filter. To this add first the 
sulphate of iron, then the sulphuric acid, and lastly the indigo 
paste. Care must be taken that the indigo does not contain 
much free acid. This is also a good copyifig ink. 

Indestructible Ink for resisting the action of corrosive sub- 
stances : Twenty-five grains of copal in powder are to be dis- 
solved in two hundred grains of oil of lavender, by the assistance 
of a gentle heat, and are then to be mixed with two and a 
half grains of lampblack, and a half grain of indigo. 

6. Copying Inks, — i. Three parts by weight of white gly- 
cerine ; three parts of purified white honey, best quality ; 10 
parts of violet, black, or other coloured ink. Mix up well, and 
leave the mixture to settle two or three days before using. 2. 



26o MISCELLANEOUS CHEMICAL PROCESSES 

Four parts by weight of white glycerine ; four parts of purified 
white honey, best quality ; ten parts of Robertson's ink ; a half 
part of powdered gum arabic. Add one or two drops of strong 
solution of bichloride of mercury to prevent deterioration of the 
ink ; stir up well, and leave it to settle for two or three days 
before using. If it should be found, in taking copies from ink 
according to recipe No. i, that thicker characters are produced 
than those of the original, the proportions of glycerine and 
honey may be respectively reduced to two parts of each, or 
another quarter by weight of one part powdered gum arabic 
may be added. 

Indelible Ink. — i. A very good indelible black ink, capable 
of resisting chlorine, oxalic acid, and ablution with a hair pen- 
cil or sponge, may be made by mixing some of the ink made 
by the preceding prescription, with a little genuine China ink. 
It writes well. Many other formulae have been given for in- 
delible inks, but they are all inferior in simplicity and useful- 
ness to the one now prescribed. 

Solution of nitrate of silver thickened with gum, and written 
with upon linen or cotton cloth, previously imbued with a solu- 
tion of soda, and dried, is the ordinary permanent ink of the 
shops. Before the cloths are washed, the writing should be 
exposed to the sunbeam, or to bright daylight, which blackens 
and fixes the oxide of silver. It is easily discharged by chlo- 
rine and ammonia. 2. A good permanent ink may be made 
by mixing a strong solution of chloride of platinum with a little 
potash sugar, and gum to thicken. The writing made there- 
with should be passed over with a hot smoothing-iron to fix it. 
3. Nitrate of silver, i to 2 drs. ; water, |- oz. ; dissolve, add as 
much of the strongest ammonia-water as will dissolve the pre- 
cipitate formed on its first addition, then further add mucilage 
I or 2 drs., and a little sap green to colour. Writing executed 
with this ink turns black on being passed over a hot Italian 
iron. 4. Asphaltum, i part ; oil of turpentine, 4 parts ; dis- 
solve, and colour with printers' ink. Very permanent. 5. 20 
grains of sugar dissolved in 30 grains of water, and the ad- 
dition to the solution of a few drops of concentrated sulphuric 
acid ; the mixture is then heated, when the sugar is carbonized 
by the action of the acid. It is said that the writing is not 
only of a solid black colour, but that the acid resists the action 
of chemical agents. 



AND COMPOSITIONS. 261 

Permanent Ink for Writing in Relief on Zinc. — Bichloride 
of platinum, dry, one part ; gum arabic, one part ; distilled 
water, ten parts. The letters traced upon zinc with this solu- 
tion turn black immediately. The black characters resist the 
action of weak acids, of rain, or of the elements in general, and 
the liquid is thus adapted for making signs, labels, or tags 
which are liable to exposure. To bring out the letters in relief, 
immerse the zinc tag in a weak acid for a few moments. The 
writing is not attacked, while the metal is dissolved away. 

Blacking. — Liquid Blacking, — i. Boil i oz. each of powdered 
galls, starch, and copperas, and 2 oz. of white Castile soap, 
with 2 quarts of water ; then strain and mix with 3 oz. of fine 
ivory-black and 6 oz. of molasses. 2. Ivory or bone blaqk, 2 lbs. ; 
neat's-foot oil, 4 oz. ; mix, and add 3 quarts of sour beer or 
vinegar, and a spoonful of any kind of spirit ; stir till smooth, 
add 2 oz. of oil of vitriol, and sprinkle on it ^ dr. powdered 
resin. Then boil together 3 pints of sour ale with a little log- 
wood, and \ ounce of Prussian blue, 3 oz. of honey, and 8 oz. 
of treacle ; mix, but do not bottle for two or three days. 3. 
Ivory or bone black, 8 oz. ; brown sugar or treacle, 8 oz. ; 
sweet oil, i oz. ; oil of vitriol, ^ oz. ; vinegar, 2 quarts ; mix 
the oil with the treacle, then add the oil of vitriol and vinegar, 
and lastly the black. 

Paste Blacking. — Powdered bone-black is mixed with half 
its weight of molasses, and one-eighth of its weight of olive oil, 
and to this is afterwards added one-eighth of its weight of 
hydrochloric acid, and one-fourth of its weight of strong sul- 
phuric acid. The whole is to be then mixed up with water 
into an unctuous paste. 

Blacking for Harness. — Take 4 oz. of black resin, and put it 
in a glazed pipkin over a slow fire ; when melted, add 6 oz. of 
beeswax. When the beeswax is melted, take it off the fire, 
and add i dr. of Prussian blue in powder and i oz. of lamp- 
black ; stir till perfectly mixed, and add turpentine until it be- 
comes a thin paste, then let it cool. When required to be used, 
rub it over the harness, and polish with a soft brush. 

Piecing Indianibber. — Make a long bevel on the ends you 
wish to join (with a sharp, rough-edged knife and water), scrape 
the bevels rough with the edge of the knife, and when quite 
dry, give each a coat of indianibber solution — sav i oz. of 



262 LIGHTING. 



rubber, not vulcanized; to 5 oz. of turpentine. When the first 
coat is dry, give it another ; and when that is dry, he may put 
the two ends together. It is impossible to make a firmer joint 
than by this method. 

Vulcanized Indiarubber. — It is impossible to manufacture 
vulcanized indiarubber that shall be free from odour, and not 
liable to become rotten. With regard to smell, a good deal 
can be done towards making it agreeable by exposure to the 
atmosphere, and by desulphurization ; but the best plan is to 
scent it in the manufacture, and so disguise the natural smell. 
With regard to rubber becoming rotten or decomposing, it is a 
question of manufacture and exposure to the sun's rays, which 
is the most powerful agent in effecting the decomposition. The 
red rubber is as liable to become rotten as any other of the 
same specific gravity. It also has the ordinary odour of vul- 
canized indiarubber, unless artificially scented. 

Bones for Manure, Preparation of. — Illienkof, a Russian 
chemist, gives the following process, which, it is said, has 
received the approbation of Liebig : — The author mixes 4000 
kilos, of ground bones with 4000 kilos, of wood ashes contain- 
ing 10 per cent, of carbonate of potash, and adds 600 kilos, of 
quicklime. This mixture he places in a tank or fosse with 
water sufficient to make the whole moist. In a short time the 
bony matter is completely disaggregated by the caustic potash, 
and the pasty mass formed is then taken from the tank, dried, 
mixed with an equal weight of mould, and is then ready to be 
distributed. 

Chimney Lamp. — Some chimneys will last for months, 
while others, apparently as sound and good, will break after a 
short use, without any apparent cause. The great cause of 
their being brittle and breaking so easily lies in the material 
they are made from. There is *' shoddy " in glass as w^ell as 
in cloth. A great many manufacturers make chimneys from 
silicate of lime instead of silicate of lead. The glass made 
from the silicate of lime has about the following proportions : — 
Sand, 100 ; soda, 45 ; lime, 20 to 25 ; nitre, 7 to 10. Lime 
being a non-conductor of heat, the chimney will not bear the 
expansion caused by the heat ; and if, by gradual heating, the 
chimney does not break on the lamp, a few times heating 



LIGHTING, 



203 



makes it so brittle that it breaks with the least effort at cleaning 
it, no matter how much care is used. The silicate of lead has 
about the following proportions: — Sand, 100; lead, 40 to 50; 
soda, 20 to 25 ; nitre, 10 to 15. Lead being very ductile, and 
a good conductor of heat, a chimney made from this formula 
will almost melt before it will crack with the heat. The 
uninitiated may tell the difference of the chimneys made of 
these different qualities of glass by ringing them ; the vibration 
from the lead glass chimney has a sweet, bell-like sound, whilst 
the lime glass has a short, harsh sound. The difference of the 
cost of manufacture is only, in material, about 8d. per dozen. 
Another point is in annealing ; chimneys as a general rule are 
not annealed ; under a powerful microscope the difference can 
be seen in the glass ; the particles in the annealed glass lie close 
and compact, while the unannealed seem ready to diverge. 



F'.G J 



Glass Chimneys, Why they Break. — The shattering of gas 
chimneys is caused by sudden and excessive change of tempera- 
ture. If, on extinguishing the light, the chimneys are allowed 
to cool slowly, the spontaneous shattering complained of will 
not occur. A slit made by a diamond along the whole length 
of the chimney will 
often save the glass 
from such rupture. 
If the glasses were, 
on being taken down, 
embedded, while still 
hot, in hot ashes or 
other such material, 
and thus left to cool 
slowly, less breakage 
would occur. 

Hydrogen Lamp. 

— The following pro- 
duces a flame with 
good heat, but not 
good light. G is a 
glass or earthenware 

vessel, with air-tight brass top, in which is screwed. the valve 
V ; and T the tube which contains the piece of spongy platina 




264 



LIGHTING. 



S ; Z is a ball of zinc, suspended in the inner vessel I ; H is 
a hole to permit the air to pass to and fro ; and D, dilute 
sulphuric acid ; p and p show the relative positions of the same 
in the two vessels G and I, when the valve is closed. The dilute 
acid acting on the zinc gives off hydrogen, which, having no 
way to escape, forces the liquid into the outer vessel, and so 
prevents any further chemical action until the valve is opened, 
when the pressure of the atmosphere forces the acid to attain 
an equal level in both vessels, and so forces the hydrogen out 
at the nozzle and through the tube, causing the platina to 
become red hot and ignite the gas. 



The "A B C '' Gas Meter. — This meter has attached to it 
an index which performs at once the double duty of giving the 
consumption of gas and the price thereof. In the sketch is 




p^.B.C CAS 



PATENT 



M^ 



AMOUNT PAYABLE FOR GAS AT 5/ 

S 




PER 1.000 FEET 




CUBIC 




FEET 



shown the patent index: 5250 ft. are supposed to have been 
consumed, and the money payable at the assumed price of 5s. 
per 1000 ft. is ^i, 6s. 3d., as indicated. As i6| ft. from 
the 3d. gradually changes to 4d., and so on for every i6| ft. 
consumed, till the quantity amounts to 5400 ft., when ** 7 " 
appears under the shillings' heading and ** o " under the pence, 



DYES. 265 



the total being ^i, 7s., and so on for any larger quantity. 
This index should prevent all disputes as to cost. It is intended 
that the registration should be continuous, but that the cash 
index should, upon each quarterly taking of the state of the 
meter, be put back to zero, and a ticket of the cash, as well as 
the number of feet to be charged, to be left with the consumer ; 
the one will be a check on the other. When the price of gas 
is changed, the index can be altered at a trifling charge, and 
old meters may have the cash index added for about a crowru 
The manufactory is at the Meter Company's Works, Johnson's 
Place, Lupus Street, Pimlico. 

Water in Gas-Pipes. — Where the pipes have been properly 
laid (that is, inclining every way to the meter) it is impossible 
for the water to remain in gas-pipes. But it is possible that 
the water may have condensed in the pipes in sufficient quan- 
tity to run back into the meter, and raise the water in it above 
the proper level ; in that case the lights would certainly go out. 
The remedy is to unscrew the plug of the meter, and let the 
surplus water run out. 

Removal of Bisulphide of Carbon from Coal G-as. — This 
substance imparts a very disagreeable odour to gas, and the 
sulphur it contains is, during combustion, changed into sul- 
phurous acid, which is injurious to animal life, destroys vege- 
table colours, &c. The bisulphide is a highly volatile liquid, 
and its entire removal from gas has been hitherto extremely 
difficult, if not impossible. Mr Lewis Thomson, however, has 
found that it may be entirely got rid of by passing the gas, 
after it has left the hydraulic main, and before it enters the 
condenser, along with a certain quantity of steam, through a 
tube or retort of cast iron, heated to about 1200° Fahr. 
The vapour of water and the bisulphide then mutually decom- 
pose each other, sulphuretted hydrogen and carbonic acid 
being formed. Both these are removed in the usual way. 

Royal Blue Dye for Silk. — Into a tub partly filled with 
cold water pour 2 pints of nitrate of iron ; then take i pint of 
water and ^ pint of muriatic acid; to this add 3 oz. of crys- 
tals of tin ; when dissolved, pour it into the vessel containing 
the iron solution, stir well, throw in the silk, and work for some 
time. In another tub dissolve 8 oz. of yellow prussiate of 



266 DYES. 



potash, and add to it 2 oz. (by measure) of vitriol ; the silk is 
wrung out dry from the iron solution and put directly into the 
prussiate solution, in which it is worked for some time. It is 
then washed in cold water with 2 oz. of alum dissolved in it. If 
the dye is not dark enough, instead of being washed in the 
alum-water, the silk may be put into the iron again and through 
the prussiate in the same way, and worked for about the same 
time as before, but add a little more prussiate. Deeper shades 
are obtained by using more iron and tin, or by giving several 
dips. The silk must be perfectly freed from grease before com- 
mencing the dyeing operation. The mixture above recom- 
mended will dye 5 lbs. weight of silk. 

Dyes for Woollens. — For 60 lbs. of woollen yarn take 2 lbs. 
of flavine, 6 lbs. of alum, i lb. of tin crystals. Dissolve in boil- 
ing water. Then dissolve separately 4 oz. of red prussiate of 
potash, and add it to the above. Then add 4|- lbs. extract 
of indigo and 1 2 oz. oxalic acid. Dye in the usual manner. 
This makes a full green. For deep scarlet take 3 J gallons of 
cochineal liquor, containing i J lbs. of cochineal per gallon, 36 
oz. of starch. Boil, and add ^ pint of mixed berry and fustic 
liquor at 15°, i lb. bin-oxalate of potash, 3 oz. of crystals of tin, 
and 12 oz. of bichloride of tin at 100°. 

For Black Silk and Wool. — Silk to be dyed black must be 
first washed free from grease, and then gently boiled for half 
an hour in a dilute solution of nitrate of iron. Take out and 
rinse in cold water, and then boil with logwood of half the 
weight of the silk itself for one hour. To dye wool black, boil 
it with its own weight of logwood for an hour, and then add 
sulphate of iron in the proportion of about one pound to every 
thirty of wool. 

For Ostrich Feathers, &c. — For ostrich feather dyeing, 
first expose them to sulphur-vapour to bleach them, then dye. 
Black. — Immerse for two or three days in a bath (hot at first), 
of logwood eight parts and copperas or acetate of iron about 
one part. Blue. — The indigo vat. Brow ft. — Any brown dyes 
for silk or wool. CrUnson. — A mordant of alum followed by a 
hot bath of Brazil wood and a weak one of cudbear. Pifik or 
Rose. — Safflower and lemon juice. Plum, — Red dye followed 
by an akaline bath. Red, — Alum mordant and a hot Brazil- 



DYES. 267 



wood bath. Yellow, — Alum mordant turmeric bath. Other 
shades by mixtures. 

Aniline Dyes. — The colouring-matters produced from ani- 
line and analogous matters are all, with the exception of the 
Fuchsine and Perkins's violet, insoluble in water, and many 
attempts have been made to substitute a less costly solvent for 
the alcohol hitherto employed. M. Gaultier de Claubry, a 
French chemist, has recently taken out a patent for a method 
of accomplishing this. He says that a great number of sub- 
stances, such as gum, mucilage, almond, and other soap, glu- 
cose, dextrine, the gelatinous portion of various feculae, of 
lichens, and of fuci, render water a solvent of such colouring- 
matter, but that the best and most economical results are to be 
obtained by means of de.coctions of the bark known as Panama 
{Qidllaia saponartd), or of the root of the Egyptian soap-plant 
{Gypsophila strutiuni). The Saponaria officinalis^ he adds, 
may be employed, but is less energetic in its action than the 
other two. The solutions are obtained by pouring the boiling 
liquors upon the colouring-matter in powder, agitating, decant- 
ing, and, if the solution be not complete, repeating the process. 
The solutions thus obtained may be reduced to extracts by 
evaporation, but continued ebullition, especially " if the water 
contain sulphate or carbonate of lime, may injure the colours. 
A better method, according to M. Gaultier de Claubry, is to 
triturate the powdered colouring-matter with the extract of 
Gypsophila strutium^ and then afterwards to add water by de- 
grees ; but as the reds dissolve more readily than the blues, it 
is necessary afterwards to mix all the products together. The 
solutions obtained by means of the extracts above-named are 
said to work readily with gum, dextrine, and albumen, sepa- 
rately or combined. The advantages claimed for the process 
by the patentee are economy, perfect unity of tints, which will 
not soil linen by contact, and suppression of inconvenience 
caused to the dyers by the use of alcohol or wood-spirit. In 
connection with the latter, it should be mentioned that the at- 
tempt to substitute it for alcohol has been defeated by the 
workmen, who have, in many instances, refused to use it on 
account of its effect on their health. 

To Colour Straw Black. — The quantities are intended for 
twenty-five hats or bonnets. The articles are kept for two 



268 WATERPROOFING. 



hours in a boiling decoction of 4 lbs. of logwood, i lb. of su- 
mach, and of 5 oz. of fustic ; afterwards they are dipped into a 
solution of nitrate of iron, then well rinsed with water, and 
when dry, are painted over with a solution of gum or dextrine. 
The iron liquor, as well as the other ingredients, are kept by 
all dealers in dye-stuffs. 

Printed Cottons, to Wash. — Infuse three gills of salt in 
four quarts of water ; put the cotton goods in while hot, and 
leave till cold, and in this way the colours are rendered perma- 
nent, and will not fade by subsequent washing. 

Bleaching- Powder. — When hydrate of lime, very slightly 
moist, is exposed to chlorine gas, the latter is eagerly absorbed, 
and a compound produced which has attracted a great deal of 
attention ; this is the bleaching-powder of commerce, now 
manufactured on an immense scale, for bleaching linen and 
cotton goods. It is requisite in preparing this substance, to 
avoid with the greatest care all elevation of temperature, which 
may be easily done by slowly supplying the chlorine in the first 
instance. The product, when freshly and well prepared, is a 
soft, white powder, which attracts moisture from the air, and 
exhales an odour sensibly different from that of chlorine. It is 
soluble in about ten parts of water ; the unaltered hydrate being 
left behind, the solution is highly alkaline, and bleaches feebly. 
When hydrate of lime is suspended in cold water, and chlorine 
gas transmitted through the mixture, the lime is gradually dis- 
solved, and the same peculiar bleaching compound produced. 

Waterproofing with Paraffin. — The materials which in 
modern times were first employed for waterproofing were bees- 
wax and the various kinds of drying oil, especially linseed oil, 
which were rendered more siccative by boiling or some other 
of the processes usually employed for that purpose. About 
forty years ago caoutchouc was first successfully used, for ren- 
dering fabrics and other materials waterproof, by the late Mr 
Charles Macintosh ; and after an interval of about twenty 
years, gutta-percha was first imported into this country, and 
immediately applied for similar purposes. In 1832 paraffin 
was discovered by Reichenbach in the course of his admirable 
researches on wood and coal tars ; he, however, only succeeded 
in obtaining it in very small quantity, so that for a long time 



WATERPROOFING. 269 



it was only known as a chemical curiosity. It is to Mr James 
Young that we are indebted for the production of this material 
on an industrial scale, by his process which he patented nearly 
fifteen years ago. 

A few years ago a patent was taken out by Dr Stenhouse for 
employing paraffin as a means of rendering leather waterproof, 
as well as the various textile and felted fabrics ; and since then 
additional patents have been granted for an extension of, and 
improvement on the previous one, which consisted chiefly in 
combining the paraffin with various proportions of drying oil, 
it having been found that paraffin alone, especially when 
applied to fabrics, became to a considerable extent detached 
from the fibre of the cloth after a short time, owing to its great 
tendency to crystallize. The presence, however, of even a 
small quantity of drying oil causes the paraffin to adhere much 
more firmly to the texture of the cloth, from the oil gradually 
becoming converted into a tenacious resin by absorption of 
oxygen. 

In the application of paraffin for waterproofing purposes, it 
is first melted together with the requisite quantity of drying 
oil, and cast into blocks. The composition can then be applied 
to fabrics by rubbing them over with a block of it, either cold 
or gently warmed, or the mixture may be melted and laid on 
with a brush, the complete impregnation being effected by sub- 
sequently passing it between hot rollers. When this paraffin 
mixture has been applied to cloth such as that employed for 
blinds or tents, it renders it very repellent to water, although 
still pervious to air. 

Cloth paraffined in this manner forms an excellent basis for 
such articles as capes, tarpaulins, &c., which require to be 
rendered quite impervious by subsequently coating them with 
drying oil — the paraffin in a great measure preventing the well- 
known injurious influence of drying oil on the fibre of the cloth. 
The paraffin mixture can also be very advantageously applied 
to the various kinds of leather. One of the most convenient 
ways of effecting this is to coat the skins or manufactured 
articles, such as boots, shoes, harness, pump-buckets, &c., with 
the melted composition, and then to gently heat the articles 
until it is entirely absorbed. When leather is impregnated 
with the mixture, it is not only rendered perfectly waterproof, 
but also stronger and more durable. The beneficial effects of 



270 GILDING AND BRONZING, 

this process are peculiarly observable in the case of boots and 
shoes, which it renders very firm without destroying their elas- 
ticity. It therefore not only makes them exceedingly durable, 
but possesses an advantage over ordinary dubbing in not inter- 
fering with the polish of these articles, which, on the whole, it 
rather improves. The superiority of paraffin over most other 
materials for some kinds of waterproofing consists in its com- 
parative cheapness, in being easily applied, and in not materially 
altering the colour of fabrics, which in the case of light shades 
and white cloth is of very considerable importance. 

Waterproofing for Rick Cloths. — Plunge the fabric into a 
solution containing 20 per cent, of soap, and afterwards into 
another solution containing the same percentage of sulphate of 
copper ; wash the fabric, and the operation is finished. An 
indissoluble stearate, margarate or oleate of copper, is formed 
in the interstices of the tissue, which thus becomes impervious 
to moisture. This process is particularly recommended for 
rick cloths, awnings, &:c. 

Waterproofing Cotton Fabrics.— If for black work, mix 
enough lampblack and boiled oil to cover the whole surface ; 
if yellow, use yellow ochre ; add about \ lb. of driers for each 
gallon of oil. Give the cloth two or three coats of the above ; 
and if, after the last coat is dry, it should remain sticky, give it 
a coat of the following mixture : — Boil 2 lbs. of shellac in 4 
quarts of water, and add a little ammonia ; when cold, add 
lampblack or yellow ochre as required. 

Textile Fabrics, to Render Fireproof. — A very excellent 
method of rendering textile fabrics fireproof without injuring 
their colour, whatever it may be, consists in dipping them in a 
solution containing 35 per cent, gum, 35 per cent, starch, and 
30 per cent, of the compound which is obtained by dissolving 
superphosphate of lime, decomposing the salt by excess of am- 
monia, filtering, purifying with animal charcoal, concentrating 
by evaporation, decomposing with 5 per cent, silex, evaporating 
to a crystalline mass, and then drying and pulverizing. 

Electrotyping. — Wash article or mould over with a solution 
of acetate of copper, or nitrate of silver in alcohol, and then, 
without allowing it to dry, expose to the action of sulphuretted 
hydrogen gas. A sulphuret is formed which is an excellent 



GILDING AND BRONZING. 271 

conductor of electricity ; and, when dry, may be put into the 
copper bath. Minute animals and delicate objects may be 
readily coated in this way. 

To prepare the gold solution^ make a saturated solution of 
cyanide of potassium as before, and pour off this solution upon 
the contents of a 15 -grain bottle of chloride of gold until the 
latter is quite dissolved ; then dilute with water in the same 
ratio as in the silver electrolyte — that is, one part of the solution 
of chloride of gold in cyanide of potassium, with three parts of 
water. This solution filtered forms the gold electrolyte. 

Mounting the battery for plating or gilding is the next opera- 
tion. If the article or articles to be plated or gilt are small, a 
single element will, in all probability, be sufficient to produce 
the requisite amount of electric current. Place the zinc in the 
middle of the tumbler, then insert the earthenware cell in the 
zinc, and holding it down with the left hand, pour into the 
tumbler dilute sulphuric acid until it reaches to the upper rim of 
the cell. The cell itself is next filled with concentrated nitric 
acid. The plate or strip of platinum is finally inserted in the 
nitric acid. The zincs are generally amalgamated when you 
buy them ; if this operation has been omitted, you can do it 
yourself by rubbing over the moistened surfaces a cloth dipped 
in nitrate of mercury. Place one connecting-wire in the zinc 
binding- screw, and the other in the platinum binding-screw. 
The zinc wire is the negative pole, and is frequently called the 
** zincoid ;" whilst the platinum wire is the positive pole, and 
is denominated the ** platinoid." At the end of the negative 
wire the object to receive the deposit is placed by suspension 
on a hook, or otherwise, in metallic contact, and then immersed 
in the electrolyte. On the end of the positive wire either the 
piece of silver or of gold is fixed ; if the electrolyte be silver, 
the silver plate is attracted, and the gold plate in the other 
case. The silver and the gold coin can be beaten out into 
thin plates for the purpose, and then soldered to their respec- 
tive wires, or attached by drilUng holes and then suspending 
each on a hook. The objects to be gilt or plated must be 
thoroughly cleaned of all impurities, by means of a brush and 
rouge (sesqui-oxide of iron) ; and they must then be dipped in 
a solution of salts of tartar to remove grease, and finally washed 
in water. So prepared, they are suspended on the negative 
hook and immersed in the electrolyte. The plate on the 



2 72 GILDING AND BRONZING, 

positive hook is likewise immersed in the saine solution, and 
brought near to the object, but on no account in contact with it. 
The electric current now circulates, because the circuit is com- 
plete, passing along the positive wire to the plate at its end, 
where it comes in contact with the metallic solution between it 
and the object connected with the negative pole. This solu- 
tion, consisting of water and a metallic salt, is decomposed by 
the circulating current in the following manner : — The water 
is decomposed into its elements oxygen and hydrogen, which, 
being separated, rush in opposite directions, the hydrogen 
towards the object, whilst the oxygen affects the positive pole 
or plate ; and the metallic salt, infinitesimally divided by 
solution, is also broken up or decomposed into its elements ; 
thus the chloride of silver is separated into silver and chlorine, 
the latter affecting the positive pole, whilst the silver is deposited 
on the negative pole. Take out the object from time to time 
and examine it. If the coating is purely white (if silver), or 
purely yellow (if gold), the operation is going on right, and 
may continue until the requisite amount of deposition has been 
obtained. By this means the metallic film thus deposited may 
be made of any thickness whatever. Sometimes, however, this 
metallic film is not pure of its kind ; on the contrary, it is 
oftentimes granular or crystalline, and at others quite black. 
To prevent these irregularities is the electrotyper's chief care, 
and much experience and patient study are required before the 
best conditions can be obtained at once. Changing the dis- 
tance between the two poles, moving the positive pole about, 
increasing or diminishing the thickness of the positive wire, 
warming the electrolyte, diminishing or increasing the number 
of elements in the circuit ; these and other operations are at times 
necessary ; when to perform them experience alone can teach. 
As soon as the object has received the required thickness of 
deposit, it is taken out of the electrolyte, washed, dried, and 
burnished on those parts which are to appear brilliant, whilst 
the remaining parts remain dead and frosted. Burnishing 
tools are sold for such purposes ; but, in case of need, a dog's 
long tooth may be used. Rouge is used for polishing the 
object, rubbed on with a tooth-brush or wash leather. 

The operation of plating or gilding over, the next care is for 
the apparatus. The dilute sulphuric acid, once used, is thrown 
away ; but the nitric acid is poured back into the stock-bottle, 



GILDING AND BRONZING. 273 

for future use^ The latter has, however, undergone decom- 
position during the operation, and has become diluted with 
water formed by the elements liberated during the circulation 
of the electric current through the sulphuric acid and nitric 
acid ; and in consequence of this gradual dilution the nitric 
acid becomes in course of time too much impoverished for use, 
and must be replaced with concentrated acid. Place the 
porous earthenware cell in a dish of water when it is emptied, 
as also the zincs for an hour or two ; then remove them to 
drain dry. 

To Electro-Gild without a Battery. — Take \ oz. of nitric 
and \ oz. muriatic acid ; dissolve in these i dwt. of gold, gently 
evaporate until it crystallizes, then add 2 oz. of cyanide of 
potassium dissolved in 1 5 oz. of water. The article to be gilded 
is to be simply put in the solution, and a piece of clean zinc 
placed on it, and moved from one spot to another until it is 
sufficiently covered with gold. 

Gilding on Steel. — In any quantity of nitro muriatic acid 
{aqua regia) dissolve gold or platina, until, on the application 
of heat, no effervescence ensues. Evaporate the solution thus 
formed to dryness by means of a gentle heat ; then dissolve 
the dry mass thus formed in the least possible amount of water. 
Take the instrument known by chemists as a separating funnel, 
which may contain a liquid ounce ; a quarter fill it with the 
liquid, and the other three parts fill with the best sulphuric 
ether. The two liquids should not mix. Then holding the 
tube in a horizontal position, turn it round with the finger and 
thumb. When the ether has become impregnated with the 
gold or platina, which may be known by its change of colour, 
replace it in a perpendicular position, and having stopped up 
the orifice with a cork, let it stand for twenty-four hours. At 
the end of this time the liquid will be divided into two parts, 
the darkest coloured being below. Take out the cork and let 
the dark liquid flow off, and stop the tube immediately with 
the cork. What remains in the tube is the gilding liquid. 
l^he article to be gilded must be perfectly free from rust or 
grease, and have received the highest possible polish. The 
process of gilding is as follows : — A vessel of glass or unglazed 
ware having been procured, it should be filled nearly to the 
top with the gilding liquid. The article should be dipped in 

s 



274 GILDING AND BRONZING. 

this for a moment, and then be plunged into clear water and 
well rinsed. After having been thoroughly dried with blotting- 
paper, it should be placed in a temperature of 150° Fahr. until 
it is heated throughout, and then polished with rouge and wash- 
leather ; or, better still, be burnished. Take care that the 
muriate of gold is quite free from excess of acid, and be careful 
to follow exactly the above directions in every particular, as 
only by doing so can perfect success be ensured. 

Electro-Gilding for Copper Chains, &c. — Take a solution 
of nitro-muriate of gold (gold dissolved in a mixture of aqua- 
fortis and muriatic acid), and add to a gill of it a pint of ether 
or alcohol, then immerse your copper chain in it for about 
fifteen minutes, when it will be coated with a film of gold. The 
copper must be perfectly clean, and free from oxide, grease, or 
dirt, or it will not take on the gold. 

Gilding on Glass. — Glass can be gilded in two ways, by 
means of fire, and by an adhesive varnish. It is gilded by fire, 
by tempering powdered gold with borax and gum-water. The 
mixture is applied to the surface of the glass with a soft pencil 
brush ; when dry, the article is put into a stove heated to the 
temperature of an annealing oven ; the gum burns off, and the 
borax cements the gold firmly to the article by vitrification ; 
after this process, the gold on the article is burnished. Gild- 
ing is also effected by an adhesive drying varnish, which is 
prepared by dissolving gum anime in drying linseed oil. This 
mixture is diluted with some oil of turpentine, and applied as 
thin as possible to the parts that are to be gilded. When dry, 
the article is to be placed in a stove or near a fireplace, till it 
is warm enough to almost burn the fingers when handled, at 
which temperature the varnish is glutinous, and a piece of gold 
leaf applied will instantly adhere. When nearly cold, it is 
burnished ; but care must be taken to intervene a piece of very 
thin India paper between the gold and the burnisher. Gold 
size is also used as an adhesive substance. The requisite bur- 
nishing-tools can be bought at any oil and colour shop. 

Below we give four methods of performing this operation : — 

I. Take 2 oz. isinglass, and dissolve in just sufficient water to 

cover it ; when dissolved, add i quart rectified spirits of wine 

and I quart water. This size must be kept in a bottle well corked. 

Thoroughly clean and polish the glass ^ and lay it on a perfectly 



GILDING AND BRONZING, 275 

level table. With a brush dipped in the size flood the glass 
over, and then with a tip carefully lay on the gold leaf, which 
will instantly adhere to it. Then place the glass on its edge 
to dry, and leave it for twenty-four hours. On a piece of pa^r 
draw the required pattern, and with a pricker pierce holes 
along the outline. Then lay this on the gold surface, and dust 
some powdered whiting over it, so that it may penetrate the 
holes, and leave the pattern on the gold underneath. Care- 
fully remove the paper, and fill in the outlines of the design 
with gold size, mixed with orange chrome, and thinned with 
boiled oil and turpentine. When quite dry, remove the surplus 
gold with a piece of cotton wool dipped in water, and back the 
glass with the ground colour. 

2. First sketch on paper the exact size and shape of the 
figures or letters required ; then prick holes (in the outlines) 
through the paper with a pin ; take the paper and cover the 
glass on the front side with it ; now dust the paper over with 
whiting, so that it goes through the holes in the paper on to 
the glass ; remove the paper, and coat the back of the glass 
with gum size, and before the gum is dry take gold leaf and 
place it on the gum size, so that the leaf covers the dust-marks 
on the -glass. Do not be particular about the shape of the gold 
leaf then ; only see that the letters are covered. When dry, 
paint the exact shape of the letters on the back of the gold 
leaf with gold size, to which has been added some chrome 
yellow. When perfectly dry, take a little cotton wool and 
water and wash off all the superfluous gold leaf. You can 
then shade or back the letters with any colour. 

3. Make a mixture of powdered gold, borax, and gum arable 
in water, and brush the device upon the glass, earthenware, or 
porcelain with a hair pencil dipped in the above mixture ; then 
expose the article to heat in an oven or furnace, by which 
means the gum is consumed and the borax vitrified, cementing 
the gold to the glass or earthenware, after which it may be 
burnished. 

4. Breathe on the glass, apply the gold leaf, then hold a hot 
iron at the back a small distance off till all the moisture is 
dried out ; it will then assume a bright appearance. Then 
immediately paint on the back of it, or it will get dim. By 
this process no size, or anything of the kind, is needed, but 
only a little dexterity. 



276 GILDING AND BRONZING. 

Silvering Globes, Tent Mirrors, &c. — i. The mirror to be 
silvered is suspended, face downwards, in a silver bath pre- 
pared thus : — A large flat shallow vessel of glass or porcelain 
is* provided to contain the solution. One hundred and fifty 
grains of nitrate of silver are dissolved in 6 oz. of distilled 
water, and to this is added pure liquid ammonia, drop 
by drop, until the precipitate is re-dissolved. 2^ oz. of 
caustic potash are dissolved in 50 oz. of rain-water, and 
1 5 oz. of this solution are added to the ammoniacal solu- 
tion, when a brown-black precipitate is thrown down. 
Ammonia is again added, drop by drop, until this pre- 
cipitate is just re-dissolved ; and 29 oz. of distilled water are 
then added to the whole. To this mixture is again added, 
drop by drop, stirring with a glass rod, a strong solution of 
nitrate of silver, until a precipitate which does not re-dissolve 
is formed. Previous to immersing the mirror, one part by 
weight of powdered milk-sugar to ten parts by measure of dis- 
tilled water must be prepared in a separate vessel, and filtered 
until a clear solution is obtained. Then, to ten parts by 
measure of the silvering solution must be added one part by 
measure of the milk-sugar solution, and, finally, 50 oz. of the 
compound solution will be sufficient to silver a speculum 9 
inches in diameter. The glass surface should be made chemi- 
cally clean by using whiting- cream, free from grit, and rubbing 
it off, when dry, with the purest cotton ; it should then be 
wetted with dilute nitric acid, and afterwards washed with dis- 
tilled water. To suspend the mirror, a circular block of wood 
is firmly cemented to its back with marine glue or pitch, and 
three pins inserted at equal distances, to which the strings may 
be fastened. On lowering into the bath, care must be taken 
that no air-bubbles intervene, that the speculum be not deeper 
in the liquid than half its thickness, and that two inches at 
least intervene between the mirror and the bottom of the vessel. 
It should remain in the bath for four hours, by which time the 
process will be completed ; it is then removed, washed with 
distilled water, and placed to dry. It is now ready for polish- 
ing. Rub the surface gently, first with a clean pad of fine 
cotton wool, and afterwards with a similar pad covered with 
cotton velvet, which has been charged with fine rouge. 

2. The following is one of the cheapest and most durable 
methods : — Make an alloy of 10 oz. bismuth, 6 oz. lead, and 



GILDING AND BRONZING, 277 

4 oz. tin ; put a portion of this alloy into the globe, and expose 
it to a gentle heat until it melts ; then turn the globe slowly- 
round, so that an equal coating of the alloy is spread over the 
whole surface. This, when cold, will harden, and cannot be 
surpassed for durability. 

3. Take i oz. of clean lead, i oz. of fine tin, and melt them 
together in a clean iron ladle ; then immediately add i oz. of 
bismuth, skim off the dross, take the ladle from the fire, and 
before the mixture sets add 10 oz. of quicksilver, stirring all 
well together. 

4. The '' Humid Process ^^^ as it is called, is as follows : — 
Four solutions are- to be prepared — No. i. Ten grammes of 
nitrate of silver in 100 grammes of distilled water. No. 2. An 
aqueous solution of ammonia standing at 13° of Cartier's 
aerometer. No. 3. Twenty grammes of pure caustic soda in 
500 grammes of distilled water. No. 4. Into a solution of 
common white sugar there is to be poured one cubic centimetre 
of nitric acid at 36° ; it is then to be boiled for twenty minutes 
to produce interversion. There is then to be added 50 cubic 
centimetres of alcohol at 36°, and as much distilled water as 
will bring the whole to 500 cubic centimetres. Into a flask 
holding about 200 cubic centimetres there is to be poured — 

12 cubic centimetres of solution No. i. 
8 „ „ „ No. 2. 

20 „ „ „ No. 3. 

50 „ „ of distilled water. 

The liquid should remain perfectly limpid. This solution is al- 
lowed to repose for twenty-four hours. Now as to its application. 
The surface of the glass to be silvered must be scrupulously 
cleaned, and then passed over with a ball of cotton wet with 
nitric acid at 36°, and finally washed with distilled water, and 
drained from this and placed upon supports at the surface of 
a bath composed of the silvering fluid as above, to which has 
been added one-tenth or one-twelfth of its bulk of solution 
(No. 4). Under the influence of diffused daylight, the surface 
to be silvered (immersed in the bath) is seen to become first 
yellow, then brown, and in two to five minutes the silver will 
be found to be uniformly spread over the glass ; in ten or fifteen 
minutes the coat will be found to be thick enough. The glass 
is then to be washed in common and afterwards in distilled 



278 GILDING AND BRONZING. 

water, and left to dry in free air. When dry, the surface pre- 
sents a perfect metallic polish, covered, as it were, by a thin 
veil. It is then polished with chamois leather and the finest 
rouge ; a metallic surface of the utmost brilliancy will be the 
result. The gramme = 15*434 grains. Cubic centimetre = 
•165 of a cubic inch. 

Silvering Brass. — Brass and copper are the only metals 
that can be silvered without a battery. The process of silver- 
ing brass is thus described : — In 8 oz. of water dissolve 2 oz. 
of cyanide of potassium, and in the same quantity of water i 
dr. of nitrate of silver. Into the vessel containing the silver 
throw about half a spoonful of common salt ; stir this well with 
a glass rod until the silver is precipitated. Mix a little salt 
and water, and add a few drops to the solution after it has had 
time to settle. If any cloudiness follow, more salt must be 
added. When the addition of salt water has ceased to have 
any effect, carefully pour off the water and preserve the deposit. 
Wash this deposit two or three times in boiling water, and then 
carefully dry. Place this powder in a vessel, and pour on it 
about a pint of water, and add the cyanide solution about |- oz. 
at a time until the precipitate is dissolved, then add enough 
water to make about a quart. While adding the cyanide solu- 
tion stir well. If when dipping the article into this solution 
the silver deposits too quickly, more water must be added ; 
if it coats very slowly, the solution must be strengthened with 
more precipitate. This must be also done whenever the solu- 
tion becomes weak. The solution when in use should be kept 
at a temperature of from 60° to 70° of heat. After polishing 
and burnishing, the article silvered should be as brilliant and 
durable as can be wished. 

Silvering-Powder for Coating Copper. — Take 60 grains of 
nitrate of silver ; 60 grains of common salt, and 7 drs. of 
cream of tartar. Mix them, and moisten with water, and then 
apply. 

Silvering Mirrors. — The process of employing a layer of 
tin-foil and mercury, commonly but falsely called *' silvering,'' 
is as follows : — A sheet of tin-foil corresponding to the size of 
the plate of glass is evenly spread on a perfectly smooth and 
solid marble table, and every wrinkle on its surface is carefully 
rubbed down with a brush. A portion of mercury is then 



GILDTJSfG AND BRONZING. 279 

poured on, and rubbed over the foil with a clean piece of very 
soft woollen stuff, or a hare's foot, after which two rules are 
apphed to the edges and mercury poured on to the depth of a 
crown piece, when any oxide on the surface is carefully removed, 
and the sheet of glass, made perfectly clean and dry, is shd 
along over the surface of the liquid metal, so that no air, dirt, 
or oxide can possibly either remain or get between them. 
When the glass has arrived at its proper position, gentle pres- 
sure is applied, and the table sloped a little to carry off the 
waste mercury, after which it is covered with flannel and loaded 
with heavy weights. In twenty-four hours it is removed to a 
wooden table, and further slanted ; and this position is pro- 
gressively increased during a month, until it becomes perpen- 
dicular. 

Picture-Frame Stain. — To stain a picture frame black, 
procure some logwood chips, and boil them ; give your frame 
a coat of the boiling liquid. You will find this generally raise 
a roughness on the wood ; let it dry, and then use sand-paper ; 
then give it another coat of the warm liquid, and before it dries 
give it a coat of iron liquor. If you want a good job, put a 
little ivory-black in your pohsh. 

To Gild Picture Frames. — Provide yourself with the follow- 
ing articles : a cushion, made by covering a board of about 8 
in. square with a double thickness of flannel, and over that a 
piece of buff leather, and fastening it tight round the edges ; a 
palette knife, for cutting the leaves into the requisite sizes ; a 
tip, a fitch pencil, a ball of cotton, and a large cameFs-hair 
brush. The frame intended to be gilt should first be well sized, 
and then done over with seven or eight coats of size and whit- 
ing, so as to cover it with a body of considerable thickness. 
Having got a sufficient quantity of whiting on, it must be care- 
fully cleaned off, taking care to free all the cavities and hol- 
lows ; it is then to receive a coat of size, and be left till nearly 
dry. The work being thus prepared, place it a little declining 
from you, and having ready a cup of clean water, and some 
hair pencils, moisten a part of the work, and apply the gold 
leaf by the tip to the part. * The gold will immediately adhere, 
and is then to be pressed down by the ball of cotton. Proceed 
thus until the whole is finished, leave by for twenty-four hours, 
and then burnish the prominent parts with an agate burnisher. 



28o GILDING AND BRONZING, 

Gilding and Plating. — The following instructions are con- 
densed from an article by Professor Towler, a capable and 
experienced instructor : — 

The first thing required is a galvanic battery. There is a 
great variety of galvanic batteries to be had, but we prefer a 
Grove's battery. A single element consists of a cylinder of 
zinc, a thin plate of platinum, a tumbler, a cell of porous or 
unglazed earthenware, two binding-screws, two solutions (dilute 
sulphuric acid and concentrated nitric acid), two connecting- 
wires, and a plate of silver and one of gold (a two-shilling piece 
for one, and a gold dollar for the other). Two of these elements 
will be sufficient for almost all ordinary operations of gilding, 
and sometimes only one is required. The zincs, plates of pla- 
tinum, porous cells, binding-screws, tumblers, and connecting- 
wires, can be bought already prepared for electrolyte operations 
and ready for mounting. Mix one fluid ounce of commercial 
sulphuric acid with ten fluid ounces of water for one solution. 
The strongest aquafortis or commercial nitric acid is suitable 
for the other solution. 

In the second place a silver and a gold solution have to be 
prepared, and kept on hand ready for use. Each of these solu- 
tions is denominated an electrolyte, and the art of decomposing 
such a solution by means of an electric current is known by the 
name of electrolysis. To prepare the silver solution^ take a 
solution of nitrate of silver, and add to it a solution of common 
salt as long as any white precipitate is produced. Perform this 
operation in a darkened room, because the white precipitate 
(chloride of silver) is very sensitive to light, thereby changing 
into a violet-coloured powder, which is insoluble in the fluid 
into which it is subsequently mixed. As soon as the precipitate 
has completely subsided, pour off the supernatant fluid, and 
add to it a few drops of the salt solution ; if no milkiness is 
produced, the silver has all been removed as chloride, and con- 
sequently the fluid may be thrown away as useless. Mix the 
white chloride with rain-water, and stir the mixture with a glass 
rod, and allow the precipitate to settle again ; this is called 
washing the precipitate. When the precipitate has subsided, 
the fluid part is poured off, and the residue is again washed. 
This operation is repeated several times, and the chloride, 
finally separated by decantation from the wash-water, is ready 
for the next treatment. Make a saturated solution of cyanide 



GILDING AND BRONZING, 



281 



of potassium in rain-water — that is, add lumps of the cyanide 
as long as it is dissolved, and finally a small part is left undis- 
solved. The water is then saturated with the salt. Pour this 
saturated solution of the cyanide upon the chloride of silver, 
and keep pouring and stirring until the chloride is entirely 
dissolved. Filter the solution, and dilute as follows : — Silver 
electrolyte : saturated solution of the chloride of silver in 
cyanide of potassium, 4 oz. ; rain-water, 12 oz. The solution 
is then ready for use. 



Picture- Frame Making. — The following is a simple and 
easy plan for making picture frames. Take a common deal 
board 9 in. wide and i in. thick ; cut it into four slips, run a 
rabbit plane on one edge, for the glass, picture, and back to fit 
into. Cut it into lengths, according to the size of the pictures ; 
countersink the sides into the top and bottom ; one screw in 
each angle, put in from the back, will keep them firmly to- 
gether. A cord round the projections at the top will serve to 
hang the picture. 

Deal may be stained a dark oak-colour, by giving it two or 
three coats of a solution of i oz. bichromate of potass, and 2 
oz. of bluestone, in 
1 2 oz. of water ; 
after which, apply 
plain drying oil, and 
finish with copal 
varnish. The oil 
deepens the colour 
and brings out the 
natural graining. 

For clamping pic- 
ture frames, pro- 
ceed thus : — Cut 
four pieces as No. i ; 
drill a hole through 
as shown ; cut a 
small channel as 
shown ; cut two pieces as No. 2 and 3 six inches long ; drill No. 
2 half-way through for end of screw, the same as the ordinary 
clamp. No. 3 is to be tapped to fit screw. In addition 
two small holes same size as through angles and as shown. 




2S2 



GILDING AND BRONZING. 



Get a length of catgut about | in. thick. Put it through the 
angles and No. 3. Before glueing, see that the catgut is about 
the size of the frame. Then glue and put the angle-pieces on, 
and screw up as shown in No. 4. They can all be made of 
beech i in. thick. This plan is expensive, and rather slow. 
Prints must have a glass over them, and so be secured from 
the entrance of dust, liies, and damp. The glass of each frame 
is laid in with a composition like plaster, blackened to suit the 
dark frames ; and, besides this, glass is pasted all round inside 
to the frame with a narrow strip of paper. Within the glass is 
the gilt moulding, which thus serves to keep the print and the 
glass a quarter of an inch apart. The print, being attached by 
its edges, or its corners, to the backboard, is put in over the gilt 
moulding, and the whole of the back securely pasted over with 
strong paper. The only prints that turn yellow are those pasted 
on to canvas stretchers. This is probably caused by the paste. 
The paste to be used for all prints and drawings should be 

shoemakers' paste, 
which has alum in 
it; and besides, not 
breeding insects, 
will attach paper to 
wood thoroughly. 
The putty, paste, 
&c., used must be 
quite dried after 
each part of the 
process of framing, 
before proceeding 
to paste up the back. 
The print itself must 
be also thoroughly 
dried. The best 
composition for pic- 
ture-frame cornices 
is composed of size and whiting. The best size is made by 
well-soaking buffalo skin, and then boiling it to the consistency 
of jelly. For touching up old frames the common size will do. 




Compo Ornaments for Picture Frames 

water boil 3 J lbs 



of the best glu^, and in 



-In a quart of 
3 gills of raw 



GILDING AND BRONZING, fSTj 

linseed oil melt i|- lbs. of white resin. When these ingredients 
are well boiled, let them simmer together in a large vessel for 
about half an hour, stirring the mixture, and taking care it does 
not boil over. When this is done, pour out the mixture into a 
large quantity of finely-ground whiting, and roll it to the con- 
sistency of dough, and it is then ready for use. 

Composition Orna7ne7its, — Dissolve ^ lb. of glue in 2 quarts 
of water. Boil together i lb. of resin, \ gill of Venice turpen- 
tine, and I gill of linseed oil. Put these two mixtures into one 
kettle, and boil together, stirring well until all the water has 
evaporated ; then add finely-powdered whiting until the mass 
has attained the consistency of putty. This composition 
becomes hard when cold, but when warm may be readily 
moulded to any pattern required, and is more durable than 
wood. 

Gilding Organ Pipes. — After being perfectly cleaned, the 
pipes should be painted over with flat lead colour finely ground, 
mixed with plenty of patent driers, and a little boiled linseed 
oil. (Two coats may be given, the first to be thoroughly dry 
before the second is applied.) After the second coat is 
thoroughly dry, the surface must be covered with gold size 
(which can be purchased ready prepared at the colour-shops, 
or made as directed (page 286). When the gold size 
is nearly dry, or in a " tackey '' or slightly sticky state, 
the gold leaf must be applied carefully, and pressed down 
evenly with a soft ball of cotton wool. After a short time all 
the loose particles of gold maybe removed by carefully rubbing 
with the ball of cotton wool. The coloured patterns are pro- 
duced by the following method : — Sheets of glazed paper, 
having the patterns it is desired to colour cut out, are placed 
over the gilded parts, and oil colour dabbed carefully through 
with a soft brush. The colours should be mixed with patent 
driers, turps, and very little oil, to make them flat. If two or 
more colours are desired in the pattern, papers for each diffe- 
rent colour in the pattern must be cut out. 

Imitation Silvering or Gilding. — A small quantity of melted 
tin is poured into a box, which is then closed and violently 
shaken, so as to reduce the tin to a fine powder. This powder 
is mixed with a small quantity of size or thin glue. The article 



284 GILDING AND BRONZING, 

to be gilded or silvered is then coated and allowed to nearly 
dry. Burnish with an agate burnisher, and, if required to 
imitate silver, coat with seed lac varnish ; but if to imitate gold, 
colour the varnish with a mixture of gamboge and anatto. The 
chief difficulty is to obtain the proper proportion of size to tin ; 
for if too much size is used, the burnisher will produce no effect ; 
and if too little, the tin will crumble off. 

Mosaic Gold. — To make what is termed " mosaic gold," 
heat together in a crucible or iron ladle a mixture of six parts 
of tin, three of mercury, three of sal-ammoniac, and about the 
same of flowers of sulphur. Most of these will be subKmed by 
the heat, and a solid shining substance of the appearance of 
gold will remain. 

Bronze and Bronzing. —Bronzing is of two kinds : the pur- 
pose of the one is to cover objects of all kinds with a coating 
which shall give them the appearance of bronze, while the 
other kind of bronzing modifies the surface of various metals, 
and protects them from the action of the air. The operation 
varies according to the nature of the body to be bronzed, as 
explained below. 

Bronzing Plaster Casts.— To cover plaster casts, statuettes, 
&c., with a very durable green coating, which will protect 
them against atmospheric agencies, and give them a colour 
resembling antique bronzes, employ ferro-cupreous soap, which 
is prepared thus : — A soap is made with linseed oil and caustic 
soda ; a concentrated solution of sea-salt is added, and the 
whole evaporated until the soap begins to float in grains on the 
surface ; it is then filtered through a metal strainer, and the 
grains of soap thus collected are dissolved in boiling water, and 
the solution again filtered to remove impurities. On the other 
hand, dissolve in hot water four parts of sulphate o'f copper 
and one part of sulphate of iron ; then pour the liquid into the 
solution of soap slowly, and continue to stir the mixture until 
no more precipitate is formed. This precipitate is the ferro- 
cupreous soap named above — that is to say, a mixture of 
brownish-red ferruginous soap, and a very beautiful green 
cupreous soap. These two colours, when mixed, yield a brown- 
ish-green tint, very similar to the verd antique. To purify this 
soap, collect it upon a filter, and boil it for a few minutes in the 



GILDING AND BRONZING. 285 

solution of iron and copper ; then wash it in pure boiling water, 
next in cold water, then drain and dry it as much as possible. 
To bronze a plaster cast, mix in a bain marie 30 oz. of 
refined boiled linseed oil, 16 oz. of ferro-cupreous soap (made 
as directed above), and 10 oz. of white wax ; when the mixture 
is melted, apply it with a brush upon the plaster (heated in an 
oven to a temperature of 180° to 200°). Repeat the applica- 
tion where needed, and leave the cast in the stove for a few 
minutes. The mixture thoroughly penetrates the plaster, filling 
its pores, without in any respect injuring the delicacy of detail. 
When small pieces are to be prepared, they may be immersed 
in the melted mixture, drained, and placed before the fire until 
the mixture has completely sunk into the plaster. Finish by 
rubbing the surface with a tuft of cotton. Plaster figures may 
be silvered by rubbing them with an amalgam formed of equal 
parts of mercury, bismuth, and tin, and afterwards covering 
them with a coat of pale varnish. A metallic lead-grey colour 
is imparted to the figures by brushing them over with fine 
plumbago or graphite. 

Another method, — Go over the figure with isinglass size until 
every part is covered, and the plaster has ceased to absorb. 
Then go over the whole with a stiff brush, taking care that 
none of the size lodges in the more delicate parts of the figure. 
When it is dry, with a brush containing just enough thin oil 
gold size to damp it, go over the figure, and set it aside to dry 
for about forty-eight hours. Touch then the whole figure with 
bronze powder, and let it stand for twenty-four hours ; then 
with a soft brush remove all the loose powder, particularly 
from the more prominent parts. 

Bronze Powder. — Dissolve copper filings in aquafortis ; 
when the copper has impregnated the acid, pour off the solution, 
and put into it some pieces of iron, or iron fihngs ; the effect 
of this will be to sink the powder to the bottom of the acid ; 
pour off the liquor, and wash the powder in successive quan- 
tities of fresh water. When the powder is dry, it is to be 
rubbed on the figure with a soft cloth, or piece of leather ; but 
observe that, previously to the application of the bronze powder, 
a dark blackish sort of green is to be laid on the figure ; and 
if you wish the powder to adhere stronger, mix it with gum- 
water. Lay it like paint, with a camel's-hair brush, or pre- 



286 GILDING AND BRONZING, 

viously trace the parts to be bronzed with gold size, and when 
nearly dry rub the powder over it. 

Gold Size. — Take i lb. of linseed oil, add 4 oz. gum animi 
gradually, stirring well over a clear fire until the whole is dis- 
solved. Then boil until a drop, when taken out and cooled, 
becomes as thick as tar ; strain through a coarse cloth, and 
put aside ready for use. When used, add as much Vermihon 
as will make it opaque, and thin with oil and turpentine. 

Gold Powder. — Grind leaf-gold with virgin honey until the 
leaves are thoroughly broken up and divided ; then stir the 
whole in a basin of water until the honey is dissolved. Leave 
the basin then undisturbed for a short time ; and when the gold 
has subsided, pour off the water, adding several fresh quantities 
until all the honey is washed away, after which filter and dry 
for use. 

Copper Bronze. — Copper articles are bronzed by the follow- 
ing process : — Dissolve in vinegar two parts of sal-ammoniac 
and four parts of verdigris. Boil, skim, and dilute with water 
until a white precipitate ceases to fall. Thoroughly cleanse 
the articles from grease or other impurities, and set them in a 
pan. Boil the above solution, and pour it over the articles, 
and then boil them in it until a reddish-brown colour is pro- 
duced. When this is the case, which must be ascertained by 
frequent inspection, the articles must be at once removed, and 
then repeatedly washed and dried. The solution must not be 
too strong, as should it be so, the bronze will come off with 
friction, or turn green when exposed to the atmosphere. The 
best bronze for copper is that used by urn-makers and medal- 
lists. It is essential that the preparation of iron should be of 
a good quality and free from grit, and that it shall be mixed in 
boiled clear water until it is of the thickness of cream. The 
copper articles being ready, the surface must be coated with the 
red cream, and then held over a very hot fire which is free from 
sulphur, and turned round and round so that all parts may 
come in contact as soon as possible. To perform this opera- 
tion well great practice is required. The articles are subse- 
quently burnished. 

Brown Bronze Dip. — Iron scales, i lb. ; arsenic, i oz. ; 
muriatic acid, i lb. ; zinc (solid), i oz. Let the zinc be kept 
in onlv while it is in use. 



GILDING AND BRONZING, 287 

Green Bronze Dip. — Wine vinegar, 2 quarts ; verditer green, 
2 oz. ; sal ammoniac, i oz. ; salt, 2 oz. ; alum, \ oz. ; French 
berries, 8 oz. ; boil the ingredients together. 

Olive Bronze Dip for Brass. — Nitric acid, i oz. ; muriatic 
acid, 2 oz. ; add titanium or palladium ; when the metal is 
dissolved, add 2 gallons of pure soft water to each pint of 
the solution. 

To Bronze Gun Barrels.— Dilute nitric acid with water and 
rub the gun barrels with it ; lay them by for a few days, then 
rub them with oil and polish them with beeswax. 

Green Bronze. — Bronzes steeped for several days in a strong 
solution of common salt, if washed in water and allowed to dry 
slowly, become permanently green ; or a strong solution of 
sugar with a little oxalic acid will produce the green colour. A 
dilute solution of ammonia allowed to dry on the surface pro- 
duces an evanescent green. 

Black Bronze for Brass. — Put 3^ lbs. of scales that fall 
from the red iron hammered at the blacksmith's anvil into 
7 lbs. spirits of salt, and both into an earthenware pan, in 
which let them stand for about five hours, covered close, to 
keep in the fumes ; stir it three or four times ; strain off into a 
stone bottle, into which put i \ lbs. of white powdered arsenic ; 
shake well, let it stand for a day or two, and the mixture is 
ready for use. Before using cleanse the brass from grease 
either with emery-cloth or a brush, with sand and plenty of 
water. Next dip the brass in the bronze until it is black ; then 
wash it in clean water, then in boiling water — for thus heat is 
given to dry the work and preserve the bronze. A soft black- 
lead brush is then applied with some good lead ; then the article 
is to be lacquered with a very pale lacquer and heated in an 
oven or on a hot plate to set it hard. For green do the same 
work with green lacquer for brass, to be had in any colour- 
shop. To make iron green, cleanse it first from grease, then 
give it a coat of blacklead, next one of green lacquer ; then 
make the article hot in an oven or on a plate, put on another 
coat of lacquer, and heat finally. 

Black Bronzing Iron and Steel.— The following method of 
colouring iron and steel to serve both as an ornamentation and 



288 GILDING AND BRONZING, 



preservative from rust is the discovery of M. Thirault, and has 
been successfully adopted in many factories. The following 
mixtures are not the only ones that can be employed, but are 
given as examples : — 

Liquid No. i. — A mixture of bichloride of mercury and sal- 
ammoniac. 

Liquid No. 2. — A mixture of perchloride of iron, sulphate 
of copper, nitric acid, alcohol and water. 

Liquid No. 3. — Perchloride and protochloride of mercury, 
mixed with nitric acid, alcohol and water. 

Liquid No. 4. — A weak solution of sulphide of potassium. 

A sponge is slightly moistened with liquid No. i, and rubbed 
upon the metal, previously well cleaned, and when quite dry, a 
second application of the liquid is made ; the crust of oxide 
formed upon the application of the liquid is removed by a wire 
brush, and the metal rubbed with a clean piece of rag, and this 
operation is repeated after every fresh application of the several 
liquids. Several coats of liquid No. 2 are then applied, and 
also of No. 3, with a full sponge ; and after drying for ten 
minutes, the pieces of metal are thrown into water heated 
nearly to the boiling-point, where they are allowed to remain 
five or ten minutes, according to their size. After being cleaned, 
they are again covered with several coatings of liquid No. 3, 
afterwards with a strong coating of No. 4, and again immersed 
in the bath of hot water. When removed from the bath, the 
pieces are dried and wiped several times with carded cotton, 
dipped in liquid No. 3, diluted each time with an increased 
quantity of water ; then they are rubbed with a little olive 
oil and wiped ; they are again immersed in water heated to 
140° Fahr., and upon being removed from it they are rubbed 
briskly with a woollen rag, and, lastly, with oil. The pieces 
thus treated are of a beautiful glossy black, especially if they 
have been polished. Iron and cemented steel are well adapted 
to receive this black polish ; cast steel is still better adapted 
for it, as it assumes a more uniform brilliancy. Cast iron pre- 
sents more difficulties, because it does not assume the same 
tint all over equally. 

Bronzing Wood. — First cover the wood with a uniform coat- 
ing of glue, or of drying oil, and when nearly dry the bronze 
powder, contained in a little bag, is dusted over it. This 



PYROTECHNY. 289 



bronze powder is made of various materials, such as brass, tin, 
gold, ormolu pulverized, or of metallic copper obtained in 
a pulverulent form by precipitation from its saline solutions by- 
means of iron. [The process is as follows : — They begin with 
preparing the proper alloy, either of copper and zinc or copper 
and tin, in due proportions. These alloys are cast in plates 
and hammered out into sheets by steam hammers. After they 
have been brought to the thickness of a stout sheet of paper, 
these sheets, with frequent intervening annealings, go through 
a system of rollers, from whence they go to the acid room, 
where diluted acid and washing with water removes the scale 
and stains. The cutting of the sheets into shreds is the next 
operation, after which the shreds of fine sheet metal are well 
mixed with dextrine, to avoid the dust of the next stage of 
manufacture. Powerful quartz crushers then soon reduce the 
metal to coarse powder, ready to go to the grinding and polish- 
ing mills, which consist of tempered wavy steel plates, over 
which steel rods travel at a great speed, grinding and polishing 
the bronze at the same time, and the quality or grain of the 
article is determined by the length of time to which it is sub- 
jected to the operation of these mills. Washing and straining 
the bronze powder, to get rid of accidental impurities of the 
dextrine, are the next steps, after which the bronze is put into 
bags of fine but strong cloth, and exposed to the pressure of a 
hydraulic press, to squeeze the water out and lessen its bulk. 
Drying at a low temperature and packing into pound or ounce 
packages makes the article ready for the market.] The sur- 
face of the objects is afterwards rubbed with a piece of moist 
rag, or the bronze powder may be previously mixed with the 
drying oil and applied with a brush. 

Bronzing Paper. — When bronzing paper, use gum instead of 
drying oil. When dry, the paper should be burnished. 

Pyrotechny. — A few of the simple and more effective fire- 
works are given below. The utmost care should be observed 
in all preparations of the kind — in filling, mixing, and exhibit- 
ing — as most of the ingredients are highly explosive, either on 
concussion or at a comparatively low temperature. 

Coloured Fires. — The following may be burnt open : — Red. 
— I. Nitrate of strontia 12 parts ; chlorate of potash, 3 parts ; 

T 



290 PYROTECHNY. 



shellac, i part. The strontia to be heated until deprived of its 
water of crystallization, then finely powdered. The chlorate and 
shellac also powdered, and all mixed intimately. The rationale 
of this formula is that the chlorate supplies oxygen, the shellac 
carburetted hydrogen. The perfect combustion of these gases 
gives no smell. 2. Spirits of wine burnt on finely-powdered nitrate 
of strontia. 3. Dry nitrate of strontia, 5 oz.; finely-powdered sul- 
phur, I J oz. ; chlorate of potash, 5 drs. ; sulphuret of antimony, 
4 drs. Powder the chlorate and sulphuret separately ; mix on 
paper, and add the others previously powdered. For use, mix 
some powder in a small quantity of spirits of wine. Should the 
fire burn badly, add a very little powdered lampblack or charcoal. 
Green or Blue. — When copper is burned in a hydrogen flame 
it gives a bright green colour, but the moment a little free chlo- 
rine is introduced the colour becomes a beautiful blue. 

In addition to the above, any of the simple preparations of 
colours given under *^ Rockets '' and ^^ Roman Candles " may 
be adapted for burning open. 

Roman Candles. — The cases are made by tightly winding 
stout paper around a mandril or ruler, the desired size, and 
between each wind or roll round the ruler paste should be ap- 
plied to the paper. When the case is thus made and wet, it 
must be tied round the bottom to close that aperture, and to 
form a solid bottom to work upon. 

l^oioxQ filling the case (which is the next process) introduce 
a little clay to the bottom, thereby forming a better and firmer 
bottom. Next add a little coarse powder, and cover it with paper. 
It is now ready to receive the composition which is thus made : 
— Mealed powder, \ lb. ; saltpetre, 2^ lb. ; sulphur, \ lb.; glass 
dust, \ lb. This should fill about a sixth, and be covered 
in about two-thirds of its diameter. Then add corn powder and 
a ball smaller than the diameter. More composition should now 
be added, until the case is one-third full; then paper, powder, 
and ball again until it is finished, the top being composition. 
Paste touch-paper round the hole and add a priming of powder. 
The best way of exhibiting these Roman candles is to place 
them in rows on a stand, some perpendicular, others dechning 
in divers angles, that the balls may be projected to various dis- 
tances, and produce a more splendid effect. The greatest de- 
clension should not exceed 45° or 50°. 



PYROTECHNY, 291 



Composition for the Coloured Balls. — Various forms are 
used, but the best is to make the composition into a paste, then 
roll it into shape (as directed above), and when rolled in pul- 
verized powder (whilst moist) they are ready for use. Blue 
balls or stars : — Mealed powder, 8 oz. ; saltpetre, 4 oz. ; sul- 
phur, 2^ oz. ; isinglass, 2 oz. ; spirits of wine, 2 oz. Stars or 
balls of fine colour : — Mealed powder, i oz. ; saltpetre, i oz. ; 
sulphur, I oz. ; oil of turpentine, 4 drs. ; camphor, 4 drs. 
Purple stars : — Chlorate of potash, 42 parts; saltpetre, 22^ 
parts ; sulphur, 22^ parts; black oxide of copper, 10 parts ; 
Ethiop's mineral, i\ parts. Greeji stars : — Nitrate of barytes, 
62^ parts ; sulphur, 10^ parts; potash, 23^ parts; orpiment, 
\\ parts ; charcoal, i^ parts. Yellow stars : — Nitrate of soda, 
7 4^ parts ; sulphur, 1 9^ parts ; charcoal, 6 parts. Crimson stars : 
— Chlorate of potash, 17 parts; strontian, 55 parts ; charcoal, 
4 parts ; sulphur, 1 8 parts. They may be slightly moistened 
with spirit. Great care must be taken ^ or spontaneous com- 
bustion will take place. 

Coloured Stars for Eockets.— The different fires should al- 
ways be made up wet — mixed into a rather dry paste with gum- 
water (8 oz. of gum to a pint is sufficient), and the stars 
pressed into a little mould, by which means they will do with 
much less gum-water. The proportions for the stars have been 
given thus : — Mix meal powder, 2 parts ; camphor, i part ; 
sulphur, I part ; coloured fire, moistened with oil of turpentine, 
I part. Work together in little round balls, and place in rocket. 

Sulphur and potash should never be rubbed together by 
themselves, but French poHsh enough should be used to make 
a dough, which should be rolled well on a board to the thick- 
ness of a quarter of an inch ; when dry, the dough should be 
cut into small cubes. It is better to buy the chlorate of potash 
all ready ground, and care must be taken in mixing, as it ex- 
plodes at a low temperature with all combustible substances, 
and the stars should be well dried in a tin water-bath, and the 
red stars kept in a dry well-stopped bottle. 

The various colours are made in the following propor- 
tions : — Red. — i. Dry nitrate of strontia, 72 parts ; sulphur, 20 
parts ; gunpowder, 6 parts ; coal-dust, 2 parts. 2. Nitrate of 
strontia, 1 6 parts ; chlorate of potash, 8 parts ; sulphur, 4 
parts ; charcoal (fine), i part. 



292 



PYROTECHNY, 



Rockets. — Among the most effective of fireworks are rockets. 
To make them, erect a small monkey machine, two uprights 
3 ft. 6 in. high, with head and pulley fixed in same. A piece 
of beech for monkey, 4 lbs. weight, and sliding up and down 
between uprights, being kept to its place by beads nailed to up- 
rights. A ring and cord are fixed to monkey to raise it by the 
pulley, and a pin or other contrivance for keeping the monkey 
suspended when required. 

The moulds required for supporting the cases while being 
rammed are generally cast-brass cylinders, bored to the exter- 
nal diameter of the 




I 



PIN 



RAMMERS 



CX 



7^ 



LABLE 



case. Use pieces 
of brass tube of the 
proper bore, driven 
into a hollow cylin- 
der of beech to 
support it. The foot 
of the mould is a 
cast-brass flange 



3 

8 

in. thick, with a solid 
cylinder i in. high 
for the mould to fit 
over and nipple cast 
on; thebrass spindle 
is then screwed into the nipple and the whole turned up in a 
lathe ; finally a ^-m. hole is bored through the mould i ft. |- 
in. above the bottom, through which a pin fastens the mould to 
the foot during the ramming. 

The rammers are pieces of cast bar brass turned down to i 
1 6th in. less than the internal diameter of the case, and bored 
to fit over the spindle the exact size of same ; the second ram- 
mer half way up spindle, and the exact size of the taper half 
way up ; the third rammer to be short for the solid charge 
above the spindle. It is useless to make wooden rammers, 
as they would not last under the monkey for half-a-dozen 
cases. 



FOOT 



The charges are introduced with ladles made of thin brass 
tube, with a handle driven in one end and cut obliquely at the 
other, and should contain sufficient composition to rise | of a 
diameter after ramming. 



The internal diameter of the case determines the 



length and 



PYROTECHNY, 293 



proportions of the spindle. It will be best to give the sizes 
of the cases in ounces and diameters, i oz. case, 4-ioths of 
an inch internal diameter; 2 oz. ditto, |- in. j 4 oz., 7-ioths ; 
8 oz., 9-ioths, and the thickness of the paper cases one quarter 
the internal diameter, making a 2 oz. case of | in. internal dia- 
meter I in. external ditto. 

The rule for the proportions of spindle. The length is 4^ 
times the internal diameter of case, thickness at bottom -J 
diameter, tapering to the top at one half the diameter at the 
bottom. 

The sticks should be of clean yellow pine, and of such length 
that, when tied on the rocket charged with stars, they should 
balance one another \ an inch from the mouth of the case. 
The lighter and longer the sticks are the better, but must be 
strong enough to bear the great force of the fire against them. 
2 oz. rockets 3 ft. long and \ in. square ; 4 oz. ditto, 3 ft. 6 in. 
long, and |^ in. x ^ in.; 8 oz., 5 ft. long, |- in. x | in. 

Composition for Eockets. — One of the best compositions 
for the body of sky rockets is 8 parts nitre, 3 parts charcoal, 
and 2 parts sulphur, i. For one or two-ounce rockets — i lb. 
of gunpowder, 2 oz. of charcoal, and 1^ oz. of saltpetre ; 
powder separately and mix. 2. Two to three-ounce rockets — 
to 4 oz. of gunpowder add i oz. of charcoal, or to 9 oz. of 
powder add 2 oz. of saltpetre. 3. Four-ounce rockets — to 

1 lb. of gunpowder add 4 oz. of saltpetre and i oz. of charcoal. 
4. Five or six-ounce rockets — gunpowder, 2 lbs. 5 oz. ; salt- 
petre, \ lb. ; sulphur, 2 oz. ; charcoal, 6 oz. ; and iron-filings, 

2 oz. 5. Seven or eight-ounce rockets — gunpowder, 17 oz. ; 
saltpetre, 4 oz. ; sulphur, 3 oz. 6. Eight to ten-ounce rockets 
— gunpowder, 2 lbs. 5 oz. ; saltpetre, 8 oz. ; sulphur, 2 oz. ; 
charcoal, 7 oz. ; iron-filings, 3 oz. 7. Ten or twelve-ounce 
rockets — gunpowder, i lb. i oz. ; saltpetre, 4 oz. ; sulphur, 
3^ oz. ; charcoal, i oz. 8. Twelve to fourteen-ounce rockets 
— gunpowder, 2 lbs. 4 oz. ; saltpetre, 9 oz. ; sulphur, 3 oz. ; 
charcoal, 5 oz. ; iron filings, 3 oz. 9. One-pound rockets — 
gunpowder, i lb. ; charcoal, 3 oz. ; sulphur, i oz. 10. Two- 
pound rockets — gunpowder, i lb. 4 oz. ; saltpetre, 2 oz. ; char- 
coal, 3 oz. ; sulphur, i oz. ; iron-filings, 2 oz. 11. Three- 
pound rockets — gunpowder, 4 oz. ; saltpetre, i lb. ; sulphur, 
Z% oz. ; charcoal, 2 oz. 12. For rockets of the largest size — 



294 PYROTECHNY. 



to 8 lbs. of saltpetre add 20 oz. of sulphur and 44 oz. of char- 
coal. The ingredients in each of these are to be separately 
powdered, and then thoroughly mixed. 

Another variety of composition is made thus : — For two- 
ounce rockets — meal powder, 8 oz. ; steel-filings, 2 oz. ; char- 
coal (about as fine as single F powder), i oz., rammed with 8 
blows of monkey, with a fall of 20 in. to each ladleful of charge. 
The same composition for a four-ounce rocket, reducing the 
blows of monkey to six. This is a very brilliant charge, and 
leaves a fine tail in the ascent. Eight-ounce rockets — meal 
powder, 1 6 oz. ; nitre, i o oz. ; sulphur, 2 oz. ; charcoal, 2 oz. ; 
with five blows of monkey. The solid charge over the top of 
spindle should be i^ diameter. 

Purple. — I. Chlorate of potash, 2 parts; black oxide of 
copper, I part; sulphur, i part. 2. Nitre, 25 parts; nitrate 
of strontia, 2 5 parts ; sulphur, 4 parts ; realgar, 2 parts ; 
lampblack, i part. 

Blue. — Nitre, 6 parts ; sulphuret of antimony, i part ; sul- 
phur, 2 parts ; lampblack, i part. 

Green. — i. Barium nitrate, "]"] parts; sulphur, 13 parts; 
potassium oxymuriate, 5 parts ; metallic arsenic, 3 parts ; and 
calamine, 2 parts. 2. Nitrate baryta, 16 parts ; chlorate of 
potash, 8 parts ; sulphur, 4 parts ; sulphurs of antimony, f 
part ; charcoal, ^ part. 3. Nitrate of baryta, 84 parts ; real- 
gar, 4 parts ; sulphur, 1 6 parts ; lampblack, 2 parts. 

Yellow. — Nitrate of soda, 74J parts; sulphur, 19I- parts ; 
charcoal, 6 parts. 

White. — I. Magnesium wire and chlorate of potash. 2. 
Nitre, 6 parts ; sulphur, 2 parts ; meal powder, 3 parts. 

Fire-Balloon Construction. — Procure a quantity of coloured 
tissue paper, some paste made by mixing flour with water till 
of a creamy consistence, and then boiling it till thick. 
One ounce of alum to a quartern of flour improves the 
quality. Purchase about three feet of stout wire for a hoop, a 
little light wire to suspend the sponge, tow, &c., saturated with 
spirits of wine or other light burning Hquid. Make the paper 
into gores, the shape of which can be arrived at by dividing a 
well-grown pear into six or more parts, then taking the rind off 
one of the parts and laying it flat. The greater the number of 
gores the more trouble, but the greater the probability of 



ELECTRICITY, MAGNETISM, ETC. 295 

symmetry. It is seldom advisable, however, to have more 
than tv^elve gores, unless the balloon is to be a very large one. 
Join the gores in twos ; first let them dry, and then in fours, 
and so on, never having two sides of a gore wet at the same 
time, or your patience may be tried by one side parting whilst 
the other is being pasted. When all the gores are joined, 
finish the top by pasting on it a circular piece of paper, to 
which is attached a loop of string or wire to put a stick through 
as a support during the inflation. Fasten the hoop in the neck 
with thread, pasted paper, &c. ; light and suspend the sponge. 

Pharaoh's Serpent. — This curious toy really constitutes an 
interesting chemical experiment. It consists of a little cone of 
tinfoil about an inch high. This cone is lighted at its apex, 
when there issues from it a thick, serpent-like coil, which con- 
tinues twisting and increasing in length to an almost incredible 
extent. This coil is solid, and may be handled, although it is 
very fragile. The white powder with which the cones are made 
consists of sulphocyanide of mercury, which, when heated to a 
temperature below redness, undergoes decomposition, grows in 
size, and produces a mixture of mellon (a compound of carbon 
and nitrogen), with a little sulphide of mercury. It is yellow 
on the exterior, but black within. The ^^ serpent " shape, of 
course, results from the salt being burnt in a cone of tinfoil. 

Electrical Machine, How to Make. — Having procured a 
cylinder 6^ in. long and 4 in. in diameter — cost half-a-crown 
—you will require a stand. Take a piece of wood 8 in. by 7 
in. by | of an inch thick, which will form the bottom of the 
stand. Two uprights support the cylinder. Let these be 
about 7 in. high by 3 in., and of the same thickness as the 
piece forming the bottom, and let them each have a hole made 
in them, about 5^ in. from the bottom, to admit the ends of 
the axle of the cylinder to revolve freely, but not too loosely 
within them ; these must be screwed on to the bottom piece 
(the cylinder having been first put in its place with the handle 
end to the right). The cushion is made of wash-leather stuffed 
with wool, fastened to a piece of wood 4 in. long by i^ broad 
and \ an inch thick, at right angles to another piece, so that 
when fastened to the stand it shall press softly and evenly 
against the side of the cylinder. This cushion should have 
attached to it a piece of black silk as broad as the cushion is 



296 



ELECTRICITY, MAGNETISM, 



long, and of sufficient length to hang over the cylinder to within 
^ an inch from the metallic points of the conductor. The 
cushion should fix in a hole on the front side, or the side 
nearest half to you, when the handle is to the right. When the 
machine is to be put in motion, the cushion is to be smeared 
with an amalgam which costs sixpence per oz. 

You now want a conductor. Stick some (five) pieces of wire, 
sharpened at each end, into a cylinder of wood covered with 
tinfoil. The cylinder is to be 4 in. long and i in. thick, 
rounded at each end, and fastened at right angles to a piece of 
glass rod of such a length that the points shall touch, and only 
just touch, the side of the cylinder. A piece of wire, with a 
brass ball at its extremity, is to be fastened to one end of the 

conductor, to which 
you apply the knob 
^(5) //%^ //^ ^^ ^^^ Leyden jar. 

you wish to charge. 
Paint your ma- 
chine, and every- 
thing is ready for 
operation. 

Electro - Mag- 
netic Engine. — 
PP,two permanent 
magnets ; S, a bar 
of soft iron covered 
with two coils of 
wire, a left hand 
and a right hand 
coil; MM, two 
cups with mercury; 
B, a bar to move 
in R ; a rest, with 
two arms to dip 
alternately in MM ; A, an arm being moved by W, the beam; 
F, the flywheel ; C, being stationary ; P and N the positive 
and negative poles of a battery. As soon as the current is 
set on S, the bar of soft iron is turned into a magnet, so that 
it is drawn by one of the P magnets and repelled by the other, 
next the current is set into the other coil by the movement of 




AND TELEGRAPHY. 



297 



A and B, which reverses the poles of S, the bar of soft iron, so 
that it is drawn by the magnet that repelled it before and 
repelled by the one that drew it. 

Magnetic Engine. — By this plan it will be seen that by 
enlarging GG and E, and attaching magnets, greater power 
will be obtained. When E is down, the current is sent into 
the top magnets by the spindle KKK, and drawn up again, 
and vice versd, the current never being allowed to be in both 
top and bottom magnets at the same time, which, if properly 
arranged, the spindle and springs will prevent. The soft iron, 
E, should be allowed to approach as near the faces of the 




magnets as possible, but never allowed to touch, or it will stick 
and retard speed of engine. 

AAA, the bed, to be made of hardwood ; BB, support for 
beam ; CC, the beam ; D, connecting rods ; E, soft iron plate 
for magnets to act upon ; size according to number of magnets, 
of course. FF, supports for magnets ; GG, cross piece for 
top magnets to be fastened to, and to be made of hardwood ; 
H, brass terminal clamps for the battery wires, i.e., the clamps 
that are disengaged. Ill represent magnets made of i-inch 
soft iron 4 in. long, and each core covered with five layers of 
number 16 cotton-covered copper wire. K is the spindle and 
crank motion, to which is attached two projections for making 



298 ELECTRICITY, MAGNETISM, 

and breaking contact with the springs facing them, which are 
shown at HH, and which reverse the current from one set to 
the other, one of these projections touching each spring at 
every half revolution of the spindle. 

Electro-Magnetic Engine for Small Battery Power. — A 

is the beam, B the wheel, C the pillars for wheel, DE the 
magnet, which, if the stands be about 6 in. high and the other 
parts in proportion, should be about 2^ in or 3 in. long, with 
soft iron core \ in. thick, and should be wrapped with about 
half a pound of covered copper wire. This magnet is fastened 
down on the base, between the stands, as shown ; F is one of 
two oscillating iron arms made in one piece similar to fig. 2, 
the distance between this arm F and H must slightly exceed 
the length of the magnet ; this armature must be fixed between 
the stands to oscillate on the centres K, from one side to the 

other of core of 
5^is:^^^^:=i;5:^ , FiG.l. magnet (the mag- 

net being fastened 
down between the 
two arms), thus giv- 
ing motion to the 
lever I, thence by 
means of the beam 
to the crank and 
wheel. The current 
breaker consists of 
two revolving arms 
L, which strike alternately on the spring M, two contacts being 
made during one revolution of wheel. The breaker action is 
as follows : — Suppose the wheel to revolve in the direction 
shown, and the crank to be at bottom, it will be seen on exa- 
mination that one arm of breaker will touch the spring M, thus 
completing the circuit, while the armature F will be on the left 
side of the magnetic core. The galvanic current now flowing 
through the copper wire magnetizes the core, which immediately 
attracts the armature, and draws it downward till opposite the 
core, when the breaker leaves contact with the spring, stopping 
the current and destroying the magnetism (otherwise it would 
hold the armature and prevent its moving to either side), thus 
allowing the arm to complete its oscillation, and the crank one- 




AND TELEGRAPHY. 



299 



half revolution. At this point the other arm of breaker touches 
the spring, the current again flows, the former action is repeated 
the other way, and the crank completes the remaining half 
revolution. The wire ends of magnet are connected one to one 
terminal, and the other to the spring as shown, while the other 
terminal is connected to one of the pillars of wheel, the spring 
is not allowed to touch any conducting part except the breaker 
in its revolutions. 



f\ a .1 



Electro-Magnetic Engine. — The pecuHarity of this machine 
is the construction of the electro-magnets. BB, fig. i, are two 
hollow wooden cy- 
linders, and round 
them is coiled a 
great length of co- 
vered copper wire, 
No. 16. There are 
two cores of soft 
iron, the one XPX, 
which is fixed, 
reaches half-way up 
the cylinders BB ; 
the other, KLK, is 
movable, and enters 
without friction into 
the cylinders. To 
this core is attached 
a rod R, which is 
used as a connect- 
ing-rod. In this 
engine (fig. 2) two 
of these electro- 
magnets are used, 
their movable cores, 
M K, being suspend- 
ed from the working 
beam EFG, which 
is prolonged to A, where a connecting-rod, AK, gives motion 
to the fly-wheel by the crank KL. Now, when a voltaic cur- 
rent is made to circulate in the electro-magnets, both cores 
become powerfully magnetized, and in opposite directions, 




300 ELECTRICITY, MAGNETISM, 

therefore they attract each other ; but the one being fixed, the 
other is drawn down, thus giving motion to the working beam. 
By sending a current alternately round the two electro-mag- 
nets, the beam is made to oscillate at the point F. The way 
in which the current is so changed from one electro-magnet to 
the other is thus : — The axis of the fly-wheel carries an eccen- 
tric, which gives a reciprocating motion to a slide ii^ of ivory, 
covered in a part of its length by a brass strip h ; 2, copper 
wire, ^, is bent so as to press continually on the brass strip, 
and which wire also is in communication with the zinc of the 
battery by the wire y. Two other wires, ac^ press on the slide 
ii, and communicate, one with the magnet p by the wire e, and 
the other with the magnet B by the wire g. The recipro- 
cating motion of the slide brings the strip, a^ alternately 
under the wires a and ^, so that the current is made to flow 
from the battery by the wire f^ either round the coils B, and 
by ghby to the zinc, or round the coils P and by eahby to the 
zinc. 

Simple Electrical Machine. — This consists of a disc of 
strong paper, 30 centimetres in diameter, mounted on an axis 
made of glass tube or some other nonconducting material, and 
capable of being made to revolve about fifteen times in a second 
by means of wheels, an endless band, and a handle. In front 
of the disc are two metallic rods, having pointed extremities, 
which are perpendicular to the disc, being turned towards it, 
and at equal distances from its centre. The remaining por- 
tions of the rods are bent perpendicularly, one up and the 
other down, so that the metallic balls on their other extremities 
may be at an adjustable distance from each other. The ap- 
paratus is charged by placing a sheet of paper that has been 
well dried at the fire, and electrified by friction, very near, but 
not in contact with the disc, opposite to one of the pointed 
collectors, but not at the same side of the disc. On turning 
the machine, a luminous jet will pass between the balls. If 
the disc is covered with gum lac, and sheets of paper oppo- 
sitely electrified are placed opposite the points of the collectors 
— one sheet being opposite to eacH collector — the intensity 
and duration of the effects obtained will be greatly increased. 
When the experiment is carefully made, sparks, five centimetres 
in length, will pass between the balls, and a Leyden jar, the 



AND TELEGRAPHY. 



301 



coatings of which are connected respectively with the latter, 
will be charged with great rapidity. 

Constant and Cheap Battery. — For telegraph purposes 
there are two batteries which possess these qualities in a high 
degree. The first is Mr C. V. Walker^s platinized carbon 
battery, and a modification of DanielFs. Mr Walker's is much 
used for railway telegraphs. In constructing it, it is best to 
have the graphite plate about 2 in. higher than the jars, and 
the connecting stips of copper should be well tinned and care- 
fully riveted as near as possible to the tops of the carbons, and 
then well coated with shellac varnish ; this prevents sulphate 
of copper falling into the cells. 

The second battery referred to is as follows : — i is a flat 
copper cell, having a piece of leather secured between two 
sheets of perforated copper on one side ; 2, side view of the 
same cell ; ^, cop- 
per cell ; b^ b, per- . ^. ^ copper cell 
forated copper ; c^ 
leather; 3, a cell 
of the battery com- 
plete. The whole 
of the outside of the 
copper cell should 
be well varnished, and the perforated side placed opposite a 
piece of very stout unamalgamated zinc in a stoneware or other 
jar. The outer cell is merely charged with water, and the 
copper one filled with crushed sulphate of copper moistened 
with water. It is obvious that several cells of this battery are 
required for a telegraph owing to its feeble intensity, but we 
are informed it remains constant between twelve and eighteen 
months. 

Flower-Pot Battery for Electrctyping. — Common red 
flower-pots will answer the purpose of porous battery cells. 
Wood diaphragms, ox-gullet, brown paper, prepared canvas, 
&c., have all some fatal objection, which precludes their use 
where long and constant action is desirable. The form of 
action used with success is a modification of Daniel's, wherein 
the common red flower-pot is made to do duty as a porous 
vessel, and, when properly selected and prepared, it answers 
the purpose exceedingly well. Other advantages of this battery 




302 



ELECTRICITY, MAGNETISM, 



are, that nitric and other acid fumes are dispensed with ; it is 
the least costly to construct, no amalgamation required, and is 
easy to manage in the hands of an amateur or inexperienced 
person. 

Electric Battery. — It is not necessary that the plates of 
zinc and lead be rolled up together, provided the battery jar is 
large enough to admit the plan. You cannot roll up amalga- 
mated zinc plates in consequence of their brittleness. A is the 
primary battery, B the induction coil, C the secondary battery, 
D, stand for the coil, showing the ends of the wire connected 
to the binding-screw E, on the one side, and the other end 
connected with the spring of the contact-breaker F. The other 
portion of the contact-breaker G is connected to the binding- 
screw H. The zinc of the secondary battery is connected to 

the binding-screw 



PRIMARY BATTERY 

coopEn on n A n 



SECONDARY BATTERY 




H, and the lead 
connected to the 
primary coil of wire 
as shown at I. The 
connections from 
the primary battery 
are from zinc to H, 
and copper to E. 
You will now be able to understand the arrangement, as there 
is nothing very complicated in it. J and K are wires leading 
from the secondary battery for experiments. If any other form 
of coil be used, the same plan of connections must be adhered 
to. When setting the machine in operation the screw of the 
contact-breaker must be brought in contact with the spring 
portion, and as long as the vibration of the contact-breaker 
continues the operation is going on. The peculiar arrangement 
of the connections is made in this manner, so that we may 
obtain the extra or dynamic current, which is only produced at 
each break of the contact-breaker. This extra induced current, 
being in an opposite direction to the inducting primary current, 
passes only in the direction of secondary battery. The forma- 
tion on the lead of peroxide of lead by the decomposition of 
the electrolyte causes the immense power of these batteries. 
Two plates of platinum may be used even in the place of lead 
and zinc, and then the secondary batteries are even more 



AND TELEGRAPHY. 303 

powerful. The power of the platinum batteries depends upon 
the formation of oxygen on one plate and hydrogen on the 
other. 

Earth Batteries. — Zinc and coke may be used with advan- 
tage in the formation of an earth battery. To construct one 
of this description, a sheet of zinc, about i ft. square, should 
be buried perpendicularly, about 4 ft. deep, in a moist soil, and 
the coke placed 3 in. from and parallel to the surface of the 
zinc plate. It matters little whether the wires leading from 
this battery be insulated or not ; the value of an earth battery 
depends on the moisture of the ground it may happen to be 
placed in, the strength of current diminishing on the soil be- 
coming dry, and increases when it becomes moist. 

A simple and convenient form of earth battery may be 
formed by merely burying some coke, or a copperplate in the 
ground, to form one pole of the battery, and the gas or water- 
pipe can be used for the other pole. Either of the above forms 
of earth batteries would efficiently work an electric clock of the 
usual description, very small power being required. Earth 
batteries under the most advantageous circumstances are never 
very powerful, or, to speak more correctly, they rarely exhibit 
much "" quantity,'^ whilst induction coils can only be worked 
efficiently by the use of good " quantity " currents, on account 
of the thickness of the primary wire. ^^ Smee's '^ arrangement 
of coil, of about a pint capacity, would answer. In the absence 
of information as to the gauge and length of primary wire, it 
would be well if different proportions of exciting solution were 
tried, commencing, say, from i part sulphuric acid to 1 2 water, 
up as high as i part acid to 6 water. It would then be seen 
which proportion suited the coil best. Smee gives good quality, 
is compact, easily managed, and very cleanly. 

Another method, — A coke battery will be strong enough 
without the addition of zinc, and it is not necessary for the 
wires to be insulated. In making the earth battery there are 
several ways. Dig a hole about 3 ft. deep, and put two or 
three hundred weight of coke, and attach a wire in any way to 
the coke, and attach another to a gas or water pipe, and the 
battery will be complete. Another way would be, to attach a 
wire to a gas-pipe, and another to a water-pipe. This battery 
is strong enough to drive an electric clock. Another battery 



304 ELECTRICITY, MAGNETISM, 

can be made by attaching a wire to one of the pipes, and sim- 
ply sticking the end of the other wire 3 or 4 in. in the ground; 
but the first battery will stand any length of time, and four or 
five electrical clocks have been worked at the same time on 
this battery, and is much superior to one in which copper and 
zinc plates are used. No earth battery will drive a shock 
machine. 

Artificial Magnet. — Take a piece of round inch bar, 13 
in. long, and bend it into the form of a horse shoe with the 
end strictly parallel; then get half a pound of covered copper 
wire, No. 16, and commence to wind on. The power may be 
increased by covering the iron first by winding on strips of silk, 
so that the surface of the iron is protected from contact. Leave 
a free end of about 3 feet for attachment to the battery, and 
begin about half or a quarter of an inch from the end, and 
fasten the first turn with a piece of packthread, and proceed to 
wind the wire on as closely and neatly as possible. It does 
not make any difference whether it is coiled to the right or the 
left, as it does not matter which is the north pole, and go right 
round the magnet, fastening the other end same as the first ; 
the coils round the bend will be a little open at the outside, or 
it will not come square on the second limb. You may then 
attach it to the battery, and see if all is right ; if so, varnish 
all over with red sealing-wax dissolved in spirit, and it is 
finished ; but connecting one end of the wire will not be suffi- 
cient, as it is necessary that both ends of the wire should be 
attached to the battery to complete the circuit, or the magnetic 
influence will not be set up. With this magnet you can sus- 
pend 28 lbs., using a single pair, zinc and copper, same as for 
electrotype plates 6 in. by 3^ in. ; but an increase in the bat- 
tery power would make it very much more powerful. 

Electrical Machine — Regulation Coil. — A', A^, are the 

two ends of the primary helix ; B', B^, the two ends of the 
secondary helix, which are in direct communication with the 
two binding screws to which the brass handles for administer- 
ing the shock are attached. D^, D^, are two binding screws 
to which the battery is connected. To D^ is soldered one end 
of the primary helix, but between the other end and D' the 
break must be fixed. A glance at the diagram will show the 
manner in which this is done. The brass tube used in some 



AND TELEGRAPHY. 



305 




coils for regulating the shock does so by shutting off the mag- 
netism of the core of iron wires, or rather by preventing the 
primary helix from inducing magnetism in the bundle of wires; 
and it effects its purpose nearly as well as the drawing out of 
the bundle; for brass, although an excellent conductor of elec- 
tricity, presents a most effectual barrier to magnetism, as may 
be proved by interposing a piece of plate brass between a per- 
manent magnet and its keeper, when the magnet will be found 
to attract but very 
slightly. For medi- 
cal purposes the 
current should not 
flow only in one 
direction. Copper 
in combination with 
zinc does not evolve 
nearly so much elec- 
tricity as platinized silver, but a sheet of platinized iron will 
answer nearly as well. To platinize the iron, first clean it well, 
and then pour over it a solution of platinum in nitro-muriatic 
acid, which will cover the iron with a black precipitate, which 
is platinum in a state of very fine division. The iron must 
then be well washed in clean water. Varnishing the surfaces 
of the zinc, which does not face the platinized silver or iron 
plate, must in a measure save the zinc, and not prove detri- 
mental to the power 
of the battery. To 
regulate, coil gradu- 
ally by means of a 
series of brass wires 
let into the stand, 
wind on the prim- 
ary wire in the or- 
dinary way, and 
bring out the ends 
from the secondary. Before commencing to wind the secondary 
wire, bring out the end a^ which will subsequently have to be 
soldered to the terminal b. Now lay on three layers, and with- 
out breaking the wire rub off a portion of the cotton or silk 
covering, and solder to the exposed part the wire d^ which must 
be brought through the cheek of the coil, and will be afterwards 

u 




3o6 ELECTRICITY, MAGNETISM, 

soldered to the brass knob i. Next wind two more layers on, 
and repeat the above process, bringing out another wire e, 
which will have to be connected with the knob 2 ; and continue 
winding and bringing a wire out every two layers until the coil 
is full. In the coil represented there would be eleven layers of 
secondary wire. The other secondary terminal, c, is connected 
with the sliding arm /. It will now be seen that, by turning 
the handle to i, but three layers of wire are in use ; at 2 there 
are five, and so on, until at 5 the current circulates through the 
entire number of layers, and consequently the full power of the 
coil is obtained. 

Amalgam Pad. — Take a piece of red leather 4 in. or 5 in. 
square, and spread on the middle of the rough side a small 
quantity of amalgam, to which has been added about i-6th its 
bulk of tallow. They should be well blended together, and all 
the mercury that can should be pressed out. If this pad is 
kept dry and free from dust, it will answer for a very long time. 
To excite the machine, first remove all dust from the cylinder 
and stand with a warm dry cloth. Then turn back the silk 
flap of the rubber, lay the amalgam side of the above pad on 
the top of the cylinder, holding it in its place with a slight 
pressure with one hand while turning the machine with the 
other, and it will soon speak for itself. This will be a much 
cleaner and quicker mode than putting the amalgam on the 
rubber. 

Condenser for Rhumkorff. — Take a sheet of varnished 
cartridge paper, 12 in. by 8 in., or larger if required, and lay 

on it a sheet of tin- foil 1 1 in. by 7 
in., to allow half an inch margin all 
round ; then at one corner lay a 
slip of foil 3 in. by i in. to serve 
for a connection, lay over that an- 
other sheet of varnished paper, 
then a sheet of tin-foil and a strip 
of foil in the opposite corner, and 
so continue building it up, being 
careful not to put two strips of foil following in the same 
corner, but alternately, f^rst in one, and then in the other, so as 
to connect together every other sheet. The condenser for the 
Rhumkorff consists of 50 sheets so put together, enclosed in a 




AND TELEGRAPHY. 



307 



annexed diagram. 



box for safety. The manner of connecting the condenser with 

the break of the coil may be seen in the 

The condensers are generally placed 

underneath the coil ; but that the 

manner of connecting them may be 

the more easily understood they are 

drawn at the side. In those coils 

the primary wire is laid on 



m 





CONDENSER 



separate layers, with all the ends 
brought out, and so that by connect- 
ing the handle with the first piece of 
brass, the battery current passes only through the first layer, 
thus magnetizing the iron core but little, and rendering it 
capable of inducing 
but a weak current 
in the secondary 
wire ; but as the 
handle is moved on- 
wards each succes- 
sive piece of brass 
connects one more layer of primary wire, until at the last all 
the layers are connected, and the core becomes, when the cur- 
rent passes, highly 
magnetized, and 
capable of inducing 
a strong secondary 
current. 

Another machine 
for covering wire 
with cotton, silk, 
&c., is made en- 
tirely of deal. A is 
a tube for carrying 
the wire through; 
B is a wood disc, 
which can be glued 
on A, carrying one 
or any number of 
reels; B,the cover- 
ing material, which 
is passed through the disc and a wire eye, and on to the wire 




3o8 



ELECTRICITY, MAGNETISM, 



to be covered. By turning the crank with one hand, and drawing 
out wire with the other, any length of wire can be rapidly covered. 

A third machine 
for use with cotton 
is thus made : — A 
is the handle for 
driving; B, the driv- 
ing strap; C, the un- 
covered wire on the 
reel; D,J-inchtube 
conductor ; E, bob- 
bin table with cotton 
bobbins mounted ; 
F, round zinc table, 
with holes corre- 
sponding to number 
of bobbins; G is the 
receiver for the co- 
vered wire. The 
box containing the 
whole is of three- 
quarter stuff, and is 
3 feet by i^ feet. 

Another plan is 
thus described : — 
AAjSole of machine 
made of wood, into 
only one of which is 
shown. They are 
placed about 3 in. 
apart. C, upright 
frame, for carrying 
shaft D and tube 
E ; FF, two rollers 
for drawing through 
wire as it is covered; 
the top roller is 
made of lead, so as 
to give pressure to 
the wire to take it 
h rough ; E, tube or hollow spindle through which the wire 




which are mortized the two uprights BB. 




AND TELEGRAPHY, 309 

passes; GG, speer-wheel, and pinion for driving hollow spindle 
and bobbin ; HI, bracket for carrying end of hollow spindle ; 
I, endless screw for working the pulley- wheel O, fixed on the 
outer end of the under roller F ; R, support for steadying the 
wire as it passes through the spindle E ; H, bobbin containing 
the threads for covering the wire ; L is a small eye, fixed into 
the frame that carries the bobbin, through which the thread 
passes on to the wire. In using the machine, wire to be 
covered is held by the hands, and kept stretched as it is drawn 
through by the two rollers; another pair of rollers might be 
applied to keep the wire stretched the same as the drawing 
rollers. The speeds of the machine are as follows, viz. : — 
Large wheel 60 teeth, pinion 15 teeth, drawing screw 6 teeth 
to the inch, pulley for do. 35 in. diameter, drawing rollers 3 in. 
diameter. 

Electro-Magnetic Clocks. — AA is a mahogany case, with 
a glass front ; B is a metal bracket fixed to the back of the case, 
to which the pendulum D is suspended; NS are permanent steel 
magnets, fixed to the sides of the case in such a manner that 
the pendulum-ball D can vibrate freely between the poles 
of each magnet. The magnets are placed so that the poles 
of dissimilar names face each other. E is a small platinum 
ball, affixed to a brass stem, free to move to one side or the 
other, being fastened to a light spindle carried by the pendulum- 
rod at H. The plate of copper, F, is deposited in the moist 
earth, from which a wire, C, leads to the bracket B. The plate 
of zinc, G, is likewise deposited in the earth, and its wire leads 
to the piece of metal I. To the lower end of the suspension 
spring of the pendulum is attached a wire coated with silk. It 
is let down the back of the rod, which is wood, and then coiled 
longitudinally in many convolutions around the edge of the 
pendulum-ball in a groove previously made for that purpose. 

It is then taken up the back of the rod, and terminates in 
the bearings of the spindle H. The action of the apparatus 
may be explained thus : — A constant and uniform current of 
electricity would be established, and would pass through the 
earth, the plates, and wires in the direction of the arrows, so 
long as the platinum ball E rests on the platinum pin project- 
ing from the metal I. But if the pendulum is put in motion, 
suppose that, first, it were drawn aside until the ball D should 



10 



ELECTRICITY, MAGNETISM, 



be between the poles of the right-hand magnet, the point H 
being now farther to the right than the ball E, the latter would 
fall to the left and rest on the pin K, until the pendulum took 
its vibration to the left, when the ball E would fall to the right ; 
and so on continually, the action being produced by the change 
of the centre of gravitation at each vibration of the pendulum. 
This action of the ball E lets on and cuts off the flow of elec- 




tricity at or near the extreme ends of the pendulum vibrations, 
so that the convolving wire of the pendulum-ball is attracted 
and repelled by the magnets at the proper points of its vibra- 
tions, and thus a continual motion is kept up for an indefinite 
period of time. No explanation is needed of the remaining 
portion of the clock. 



AND TELEGRAPHY. 



3" 



Cheap Electric Bell. — This will work about 25 yards awa> 



from one small DanielFs cell. 
B, a small block of wood 
upon which the bell and 
magnet are placed ; C, two 
binding-screws ; D, a quarter 
of a pound of copper-covered 
wire, No. 16, for magnet; 
E, clock- spring for hammer. 



Total cost, 3s. 6d. A, bell ; 



Galvanometer. — Fig. i 
represents the machine when 
complete ; fig. 2 the coils and 
needle, made of hardened 
steel magnetized ; fig. 3 the 
needle and finger ; fig. 4 the 
skeleton coil-boxes, covered with ten layers of No. 




30 silk- 




covered copper wire, for intensity purposes, but for quantity 
they should be wound with four layers each of No. 16 cotton- 



312 



ELECTRICITY, MAGNETISM, 



covered wire. Fig's. 



5, 6, 7, should be made of ivory, brass, 



or bone, and when put together they will form the coil-box or 
frame, fig. 4, ready for winding on the wire. If the boxes are 
made of brass, they should be varnished with shellac varnish, 




sheilac and naphtha. The wire can be varnished when 
wrapped on the boxes, but the operator must be careful to 
wind the wire on both boxes, in the same direction, or he 
will not obtain any good effect. The two inside wires should 



AND TELEGRAPHY. 



313 



be joined together as at C, and the outer wires to the ter- 
minals on the case. 



Fic 5 




Fic 7 



f^^ 




Rotating Magnet. — The following is the most simple form : 
— N, S, are the poles of a horse-shoe magnet fixed on a stand, 
W ; a d is 3. wooden cup for mercury, divided into two parts, 
a and d; a is connected to one end, and d to the other, of a 




single-cell battery. C is the electro-magnet, consisting of a 
small bar of soft -iron, surrounded at its ends with a continuous 
coil of stout copper wire, the two terminations of the wire dip- 



14 



ELECTRICITY, MAGNETISM, 



ping into the mercury. The electro-magnet is supported on a 
central vertical axis, which passes through a collar, and termi- 
nates in a point, resting in a small agate cup, so that the 
electro-magnet is free to move in a horizontal plane. 

Mounting a Magnetized Needle. — Having your needle 
magnetized, cut a piece of cork cylindrical of the following 
dimensions : — Height ^ in., diameter \ in. ; push the needle 
through the cork near the top, and in the bottom of the cork 

insert a part of another needle, 
leaving the point projecting \ 
in. Balance this on the top of 
a piece of glass rod by inserting 
pins loaded with small shot op- 
posite each other on either side 
of the magnetized needle. The 
glass rod may be fastened to 
the foot of a wine-glass by 
means of a piece of gutta- 
percha, or wood, or brass. If 
the cork be varnished with seal- 
ing-wax varnish, it will be im- 
proved in appearance. The 
annexed figure will illustrate 
this arrangement. A, cork ; 
B, needle ; C, loaded pin ; D, 
the point on which the whole 
is balanced. 

Electric Telegraphy. — The 

battery, or generator of electri- 
city, is the fundamental part of 
the electric telegraph. The two 
ends or extremities of a battery 
wherein electricity is generated 
by chemical action are termed 
poles — one of them the positive 
and the other the negative. From the former the current of 
positive electricity issues, and from the latter the negative. 
Before the two metals of which a battery is composed are 
joined together no electricity is evolved, and when metallic 




AND TELEGRAPHY. 



15 



connection is established, the electricity simply makes a circuit; 
but it is the opinion of many eminent electricians that no par- 
ticular portions of that circuit can be said to be either negative 
or positive to another portion. 

There are two theories of the electric fluid — the single and 
the double fluid theory — and the student, while adhering to the 
single fluid theory, by which the action of the battery is gene- 
rally explained, may confound the existence of two different 
electrical tensions in the conductor forming the voltaic circuit, 
with the idea suggested by the terms mentioned of two distinct 
currents passing through this conductor from each of the extre- 
mities of the battery. 
Whichever theory of 
electricity is adopt- 
ed, the tQxias positive 
and negative will be 
found equally con- 
venient and expres- 
sive. To reverse the 
direction of the elec- 
tric current, or to 
transmit alternate 
currents in reverse 
directions along the 
conducting wire, are 
expressions not li- 
able to misinterpre- 
tation, if the words 
positive and negative 
are clearly under- 
stood. 

The battery most 
suitable for telegraph 
purposes is the 
" Daniell." These 

batteries are very constant, requiring very little attention, are 
not offensive in smell, and furnish a steady, reliable current. 
In making a " Daniell's battery,^' not a little care should be 
taken to obtain a porous cell free from defect. Two extremes 
have to be carefully guarded against in selecting a porous cell ; 
for either it may be over- fired, baked, or at too great a heat, 





Daniell's Battery. Pole with a variety of Insulators. 



3i6 ELECTRICITY, MAGNETISM, 

when it will not be sufficiently permeable by liquids, that is, it 
may not be so porous as to permit the liquid to pass through 
without rupture or displacement of its parts, or it may not be 
sufficiently baked, when any metallic solution will act upon and 
partly dissolve its substance. 

To prove universal porosity of a cell, it is necessary to ascer- 
tain whether water will pass slowly, but entirely, through every 
part of its texture, or by touching it with the tongue when the 
amount of dryness produced by the absorption of the moisture 
will show the freedom with which liquids will pass. The more 
porous the cell is, the greater the quantity of electricity deve- 
loped, and, therefore, the greater the quantity of metal deposited, 
as the degree of deposit is always in relation to the quantity of 
electricity generated. 

The zinc plates should be well amalgamated, and the porous 
cell supplied with a saturated solution of sulphate of copper. 
Very little acid should be added to the water in the cell con- 
taining the zinc plate. The outward vessel is formed of porce- 
lain, and consists of two battery cells. The copper element is 
immersed in a porous vessel containing sulphate of copper. 
In order to prevent as much as possible the copper solution 
passing to the adjacent cell, and its consequent action upon 
the zinc element, the porous vessel is saturated with tallow, 
excepting upon a portion of the surface which is directly oppo- 
site to the zinc plate. Instead of a porcelain vessel, battery 
cells constructed of ebonite are also employed with success. 

The quantity and intensity of the electricity in the voltaic 
pile are respectively modified by the size and number of the 
plates, and by the action of the intervening liquid. When the 
zinc plates are perfectly clean, pure water produces certain 
electrical effects. These are considerably modified by dissolv- 
ing common salt in it, or employing other saUne liquids, but 
dilute acids are best calculated to increase them. 

When the poles of the voltaic battery are brought near to 
each other in acidulated water or saline solution, or when these 
liquids are made parts of the electric circuit, so as to enable 
the electric current to pass through them, decomposition ensues, 
that is, certain elements are evolved in obedience to certain 
laws. The water, which is a combination of two gases, yields 
oxygen and hydrogen, and the neutral salts yield acid and 
alkalis. In these cases the ultimate and proximate appear at 



AND TELEGRAPHY. 317 

the poles of the battery, not indiscriminately and indifferently, 
but oxygen and acids are developed at the positive pole, and 
hydrogen and alkaline bases at the negative pole. 

The intensity of the electric current is dependent on the 
energy of the chemical action on the zinc, and the quantity 
produced in a certain space of time depends solely on the 
amount of decomposition produced, or the weight of zinc dis- 
solved in the cell, in order to increase the number of cells 
containing voltaic pairs. The nature of the exciting fluid 
materially affects the resistance which is afforded to the gal- 
vanic current, for no strength of two fluids conducts the galvanic 
power with equal facility. 

In making a galvanic battery, it is necessary to have two 
good conducting substances, separated by a good intervening 
liquid. The amount of action which it will produce will be 
proportionate to the ready action of the liquid on one substance 
and its inaction on the other, and will depend on the size and 
the power of the battery, but it is always lessened, first, by 
a slight resistance which the metals afford to the passage of the 
current; secondly, by the resistance which the intervening liquid 
is certain to afford, which is proportionate to its thickness. 

If, instead of a good conducting metal, the connection 
between the terminal plates is made by any imperfectly con- 
ducting substance or any great length of wires, then will also 
the power be still materially decreased. One cell, containing 
two metals and an intervening fluid, provided it be large, is 
sufficient to produce any amount of action where no resistance 
is afforded to the passage of the electric current. These will 
remain inactive while they do not touch ; but as soon as con- 
tact takes place, either in the exciting fluid at a distance, or 
through a fluid of more easy decomposition than the exciting 
fluid of the battery, the action immediately commences. The 
contact may be made through a great length of wire with the 
same result. In this case, however, if the wire be either long, 
of small diameter, or of a metal of no great conducting power, 
it will be seen that the hydrogen evolved from the negative 
metal will be materially lessened, showing that an obstacle is 
presented to the electric fluid. 

In constructing a line of telegraph, some discretion is neces- 
sary as regards the selection of posts for the support of the 
wires. It has been decided that it is far- better to suspend 



3i8 



ELECTRICITY, MAGNETISM, 



wires than to bury them, owing to the liability of the insulating 
material employed for the encasement of subterranean wires to 
increase the expense of repairing faults ; therefore the majority 
of our inland wires are supported on wooden posts along the 
lines of railways or canals. The poles should be at least 5 in. 
in diameter at the top, and about 1 5 feet out of the ground and 
5 feet in. The length of the posts must necessarily vary 
according to the locality in which they are placed. Young firs 
are generally used for telegraph service abroad, but in our 
country English larch is preferable. In Germany and America 
insulators have been put up on the stems of living trees, and 

found to answer 
very well. This 
idea arose from the 
fact that the sap 
ingredients of the 
tree are the prime 
movers in the rot- 
ting of dead wood, 
and, in order to 
obviate the draw- 
back to this system, 
occasioned through 
the violence with 
which trees are 
moved in heavy 
storms, Lieut.-Col. 
Chauvin construct- 
ed a swinging in- 
sulator. This con- 
trivance is hung 
upon a hook free to swing about (see engraving). The stalk is 
bent in a curve, away from the stem of the tree, that when the 
latter is deflected by wind, the line wire in swinging may not 
come into contact with it, the hook A, held in the loop B of 
bracket C, C is twisted, so that in case of a sudden jerk the 
line cannot be thrown upwards, and the insulator disengaged 
from the bracket. The hook D is also bent over the wire to 
prevent the line jumping out. This is a very ingenious con- 
trivance, and could be used with advantage in America, where 
lines have to be extended through forests. The number of 




INSULATOR 



AND TELEGRAPHY. 



319 



poles per mile average from 20 to 30. Iron posts are so 
arranged that they fit telescopically into each other ; thus they 
offer great facilities for shipment, and can also be conveyed 
either by hand or by the cheapest mode of conveyance. Being 
furnished 'with turned and bored points, they can easily be 
put together. The similar portions of the poles are inter- 
changeable. Should a 
breakage occur, the part 
which is destroyed can, 
therefore, be easily re- 
placed. 

The telescopic arrange- 
ment of the pole is also 
found advantageous in 
over-house telegraphs, as, 
after fastening the wires 
to the insulators, the pole 
can be raised or lowered 
at pleasure. The arrange- 
ment for fixing the in- ' 
sulators is admirably con- 
trived. 

The wire used for tele- 
graph lines is No. 8 gauge 
iron wire, coated with zinc, 
galvanized, in order to 
prevent oxidation or rust. 
The zinc is applied to the 
surface of the iron while 
in a state of fusion. Zinc- 
coated lines have been 
used several years. When 
the rain first falls on the 
zinc covering, an oxide of 
zinc is formed, and this 

oxide being insoluble in water, a second fall of rain cannot dis- 
solve or penetrate it. The zinc covering and the iron wire 
inside are thus prevented from rusting away. 

Insulation is the next important matter connected with the 
electric telegraph ; and although many forms of insulators, 
made of various substances, have been invented, proper insula- 




320 ELECTRICITY, MAGNETISM, 

tion of our telegraph lines has not hitherto been attained. 
When the insulators are clean, and in dry weather, there is a 
loss at every point of support. In wet weather the loss is 
increased ; and when insulation is imperfect, and heavy showers 
of rain occur, the loss is often so great as to completely suspend 
the working of the line. Certainly, much can be done by in- 
creasing the power of the batteries, still it is with difficulty that 
we can work the wires in wet or foggy weather. Glass insu- 
lators are covered with a thin film of water. Some electricity 
will escape over every insulator so covered with moisture ; in 
fact, the glass becomes a conductor. As it is exposed to humi- 
dity, it attracts to its surface the aqueous vapours of the atmo- 
sphere ; they form there a thin film of water, by which the 
electricity passes away. The first aerial insulator introduced 
in this country was an earthenware tube of the size and form 
of an ^g%, slightly flattened at the ends. The wire was passed 
through a hole in its longer axis. Porous earthenware and 
baked clay insulators are principally defective, from the fact 
that the body is so porous as readily and easily to absorb 
moisture. Whenever the glazing is broken through by the 
wire and the spike, a moist communication is at once estab- 
lished, and the insulator is highly imperfect. An objection 
somewhat similar holds against the use of gums, resins, and 
other non-conducting substances, less hard than glass, as the 
wire would soon wear through, and touch the pin upon which 
the insulator rests. The surface is also liable to gradual de- 
composition or exposure. Varley's insulator is extensively used 
in England. It consists of two cups cemented together with 
sulphur ; the outer cup is provided with a groove, to which 
the* wire is bound. In the recess of the inner cup a wrought- 
iron bolt is cemented, by which the insulator is attached to the 
bracket on the post. A further insulation is obtained by coating 
the stalk with vulcanite. The rim of the outer cup is rounded 
off inside. The purpose of this is to avoid the sprinkling of the 
interior with rain water, when a drop hanging upon the bottom 
rim is blown off by the wind. When a strong current of air 
separates a drop of water from a sharp corner, the drop is 
never carried bodily off, but bursts in the direction of the current. 
With the form given to the rim by Mr Varley, when a drop hap- 
pens to hang on that side from which the wind comes, it is driven 
a little way up between the two cups, and does not burst. 



AND TELEGRAPHY. 321 

Siemen and Halske's stretching insulator is shown in the 
diagram. It is made with a stronger and larger cast-iron bell 
than the ordinary insulator. The porcelain cup carries a stalk 
with two notches, through which the wire is drawn and wedged 
on each side, leaving a loop between them. In cold weather, 
when the line contracts, this loop allows the wire between the 
posts to be slackened, and also, in case of a rupture, gives 
sufficient space for making a joint. 

The subtle agent electricity, that we see, feel, and know to 
be moving in things around us, is composed of minute particles 
unsusceptible of any further division, electricity being in that 
respect analogous to all other kinds of matter. The inductiott 
action starts into immediate existence on the slightest disturb- 
ance of the normal electricity. Distribution shows us the wire 
of the electric telegraph under two perfectly distinct aspects. 
It seems always to have been constructed for performing two 
different functions not generally known to be separable from 
one another either in theory or in practice. The causation in 
both cases has been too profound to be understood. 

In both cases — electrical conduction, as well as electrical 
charge, distinct though they be when considered as results — 
there is in operation for attaching plus electricity to neutral 
matter a cause that we have not yet made known. Imagine a 
spherical particle of common matter to have a portion of its 
surface occupied by comparatively minute portions of electricity, 
attracted towards its centre as part of its natural electrical 
equivalent, then three things will become apparent. First, that 
the particular particle of common matter will have room to 
receive upon its surface some additional number of electrical 
particles. Secondly, that that particle, without attracting a 
larger total quantity of electricity, can attach to its surface an 
additional number of electrical particles if placed upon it, be- 
cause some part of every one that will be so placed must be 
nearer to the common centre of attraction than all the parts of 
any one of them. Under these circumstances, the parts that 
are nearest making up in their total a quantity required to 
complete the electrical equivalent will be held by attraction, 
the remaining parts not attracted by the common centre will 
be attached to the particles of matter by the indivisibility of the 
particles, and be to it a plus charge. The third thing that will 
become apparent is, that as many particles of electricity as 

X 



322 ELECTRICITY, MAGNETISM, 

shall be so placed on one side of the surface of a common par- 
ticle, in addition to its natural equivalent, may, if an adequate 
removing cause be in operation, be taken from it at the same 
or any other side without the particle of matter losing its normal 
quantity. 

Apart from the consideration of all surrounding circum- 
stances, the electrical condition of the particles of common 
matter just described may be the condition of all the particles 
throughout the whole substance of a conductor in its interior 
as well as its exterior portions. If then, in practice, we find 
the condition to be at any time limited to any particular part 
of a conductor, we must conclude that its locality is alone 
determined by surrounding circumstances for the time being. 
No conductor can appropriate to itself absolutely a single par- 
ticle of plus electricity, common matter universally having had 
assigned to it at its creation a particular and unchangeable 
quantity, so that any additional particle that may be placed 
upon it, it can only hold, as it were, in trust for some rightful 
owner, on the conditions called artificial electrical equili- 
bi'ium. 

The artificial elect7'ical equilibriM77i is that state of matter 
which becomes established whenever plus electricity, exerting 
attractions for its equivalent of common matter from which it is 
temporarily separated, acts upon surrounding non-conducting 
neutral particles virtually, though by reason of their insulating 
nature not actually dismissing from them some of their natural 
electricity, and causing the same action to be propagated to 
progressively increasing quantities of insulating matter until, 
by reason of electrical law of the squares of the quantities, the 
intensity becomes so reduced as to be insensible on our most 
delicate instruments. This, the ordinary form of artificial 
electrical equilibriu7ii, is sometimes somewhat modified by the 
intervention of neutral conducting matter, which, if it be near 
enough to sustain the induction, can actually as well as virtu- 
ally relinquish a portion of its own electricity, and thus promote 
the reduction of intensity, especially if the electricity relin- 
quished cannot pass into earth, from the surface of which it 
can act inductively with an intensity that may be regarded as 
infinitely small. As the facilities for the reduction of intensity 
increase, so will, of course, the charging capacities or quantities 
of plus electricity, susceptible of being held under any specified 



AND TELEGRAPHY, 



323 



intensity, and, owing to this law, if a conducting surface have 
contiguous to it another conducting surface communicating 
with the earth, it can receive upon it under a given intensity far 
larger quantities of charge than when it is simply surrounded 
by air. Considering, then, that the distance at which the elec- 
trical attraction may be acting between a common particle and 
its electrical equivalent is shortened by an accession of plus 
electricity, and that plus electricity on the surfaces of common 
particles can have the intensity of its attraction reduced to an 
insensible amount by induction, we can understand plus charge 
to be both possible and in perfect harmony with the doctrine of 
limited electrical attractions. Now, when we lay an insulated 
telegraph wire between two distant places, and deliver electricity 
continually into one of its extremities with greater rapidity than 
it can find its way out of the further extremity put to earth, it 
is impossible not to charge its surface, and that charge may 
have an intensity of action to any amount not exceeding the 
source from which the plus electricity is delivered. 

This is true, whether the further end of the wire be freely 
uninsulated or insulated. We can surround a long conductor 
with a cylindrical vacuum of diameter large enough to put 
common matter beyond the reach of induction, or we might 
establish a telegraph wire with perfection ; for, under such cir- 
cumstances, electricity would either not enter the wire at all, 
or only do so in order to arrive through it at some charging 
capacity at the other end, capable of holding it under an inten^ 
sity below that of the source. At the best, our telegraph wire 
has a very similar capacity for charge derived from the air 
around it. 

And even the degree of imperfection is always necessarily 
abandoned for a worse whenever the circumstances of our 
locality constrain us to convert naked wires into *^ cables'' for 
the purpose of their " interment " or submersion, for in either 
of these cases the solid insulating material by which the wires 
are enveloped for maintaining their charges is far too thin to 
keep the external conducting matter at an effectual distance, 
and thereby preventing it from dismissing by induction com- 
paratively large quantities of electricity to find on the surface 
of the earth or sea a lower intensity of charge than could 
otherwise be afforded. The greater charging capacities thus 
occasioned are known practically to give rise to evils of enor- 



324 ELECTRICITY, MAGNETISM, 

mous magnitude, and of which every telegraphist is sufficiently 
sensible. 

We now reach the laws of electrical conduction as applied 
to electro-telegraphy, and we will proceed with the following 
simple experiment. Place upon a large insulated sphere a plus 
charge, and against it on either side an end of an insulated 
rod, one of the sides being of metal and the other of glass, dry 
and clean. Part of the charge will immediately distribute 
itself over the surface of the conductor, but not over that of the 
non-conductor. Remove the glass rod, and slide the numerous 
parts of its surface into contact with the charged sphere. Then, 
upon removing it, it will be found with a plus charge distributed 
upon those parts of its surface like the other rod. In this ex- 
periment, had not conduction been a preliminary necessity, 
charge would have ensued along both sides of the rods directly 
they were placed with their extremities against the charged 
surface of the intermediate sphere, for both cylindrical surfaces 
were susceptible of charge, as is proved by the two being 
ultimately found plus electrical. It is proved that, although it 
should be possible to have conduction along a wire without 
charge with the attendant induction, we cannot have the reverse 
of this, that is, a charge on the wire or its induction, unless 
the wire has previously acted in some way as an electrical 
conductor. 

Let us now endeavour to explain more minutely the nature 
of electrical conduction along a telegraph wire. For the sake 
of simplicity of conception, suppose the insulated wire to consist 
of only a single line of particles of common matter, and that 
we present to one of its ends a quantity of plus electricity, 
emanating from a source maintained at a given intensity by 
virtue of the shortening distance, as before explained, the 
common matter of the line acting by ordinary electrical attrac- 
tions, will attach to itself the electricity so presented. 

Now, if the line be insulated at its further end, the elec- 
tricity will be held by it as a plus charge under some 
intensity, not exceeding that of the source from whence it 
is derived ; but if, on the contrary, the further end of the line 
be put to earth, or other sufficiently large mass of conducting 
matter, surrounded by air, and the supply of electricity be 
not too rapid, then conduction and not charge will ensue, for 
immediately that a particle of plus electricity enters the wire 



AND TELEGRAPHY, 



325 



at one end, another particle of electricity, natural to the other 
end, will leave it — all the common matter of the line still 
possessing its normal equivalent of electricity, because every 
one of the common particles will have acquired an electrical 
particle from its neighbour, situate between itself and the 
source of the plus charge. It may be that each of the common 
particles in the conducting line is capable of so parting with 
two, three, or some greater number of particles of electricity 
simultaneously, and in proportion as it can do so will it be the 
better electrical conductor ; but its capability in that respect 
must have a limit, and instead 
of a single line, as we have 
supposed, every wire will, of 
course, have some large num- 
ber of such lines bundled to- 
gether proportionate to the 
area of its sections ; from 
which it follows, all other con- 
ditions being constant, that its 
conductivity will be as its area 
multiplied into the number of 
electrical particles that each 
common particle can charge 
with its neighbour. So far, 
therefore, as the wire is con- 
cerned, charge and conduction 
differ chiefly in this — in the for- 
mer the plus electricity of the 
source passes from it to the 
wire to act from its surface 

with a diminished intensity on the surrounding air, and, in 
the latter case, it is handed on from particle to particle of 
the wire to be conveyed to some other conductor, having a 
charging capacity that will enable it to do the same thing ; 
and either of these results will take precedence of the other, 
as the surrounding circumstances shall enable it to be accom- 
panied by the lower intensity. If the plus electricity meet 
with less inductive reaction by remaining in the wire than by 
passing out of it, charge will take precedence of conduction ; 
on the contrary, if the plus electricity can pass out of the 
wire to a lesser amount of inductive reaction, then conduction 




Siemen and Halske's Insulator. 



326 



ELECTRICITY, MAGNETISM, 



will supersede charge, and therefore it is that conduction is 
consequent upon uninsulation and charge upon insulation of 
the wire. This is the theory of an eminent electrician of the 
present day. 

Alphabetical Dial Telegraph. — The Voltaic Alphabetical 
Dial Telegraph Instrument was formerly made by Breguet in 



F I C . I 




three separate parts, namely, the manipulator, receiver, and 
the alarum bell. The three parts are now combined in a 



AND TELEGRAPHY. 



327 



compact case. In fig. i we have a view of the case open, 
showing the face of the receiver and the plate of the manipu- 
lator with the handle. As will be seen in fig. 2, another part 
of the case is hinged, and is capable of being opened. On the 




inside of the lid of this part is screwed the bell, which is an 
ordinary *' Tremulo" bell. At the bottom of the two sides, and 
at the back of the case, are placed brass terminals, to which 
are connected the line wire, the battery wire (copper), and the 



328 ELECTRICITY, MAGNETISM, 

earth wire. By turning the handle on the dial-plate once 
round, we send, by means of a " cranked " arm not shown in 
the drawing, thirteen copper currents on the line, or half as 
many currents as there are signs on the dial-plate ; these, 
entering the instrument at the distant station, cause the hand 
or pointer on the face of the receiver to revolve once round, or 
should the handle at the sending station be stopped at any 
letter, the pointer at the receiving station will likewise stop at 
the same letter. A glance at fig. 2 will serve to show how this 
is effected. A train of clockwork, which on the average only 
requires winding up once a week, drives a common ratchet- 
wheel with thirteen teeth, the shaft of which is carried through 
to the face of the receiver, and on which the pointer is placed. 
This ratchet-wheel is released, half a tooth at a time, by a light 
rod, fitted with a catch, which is attracted to the armature of 
the electro-magnet, as it is attracted to or pulled back from the 
poles of the magnet — an attraction and a repulsion making two 
letters. When the case is closed, by means of a spring and a 
point seen at the left-hand corner of fig. i, the bell is put into 
circuit, so that when a current travels on the line the bell com- 
mences to ring, and continues to do so until the arrival of the 
clerk, who opens the case, and thus brings the receiver into 
circuit. It is possible to work these instruments at the rate 
of twelve words per minute, and a Daniell's battery of twelve 
elements is quite sufHcient for a distance of four or five 
miles. 

Simple Electric Telegraph. — The base consists of a piece 
of mahogany 8 in. square and i in. thick, with a hollow groove 

cut in its centre 2 
in. long and a half 
inch wide. The 
coil consists of 50 
ft. of covered cop- 





- 


lol- 


\ 


2 . INCI-IE.S 


Hi- r 






1 V 


^'ca|« 


1 


hi 



per wire. No. 30 
— ^ gauge, wound on a 

frame of card 1 1 in. long, \ in. broad, | in. deep in the open 
part ; an edge or flange of card \\ in. wide, 2 in. long, is stuck 
to each side to keep the wire in its place. Now commence 
winding the wire at the lower left corner, and wind from right 
to left. Each end of the wire must be stripped of the cotton, 



AND TELEGRAPHY, 



329 



a 





so as to have the wire clean for the electricity to pass. The 
coil is mounted in the stand by inserting the two lower edges 
in the groove, so that 
the floor of the coil is 
level with the stand. 
The needle is i in. 
long, I- 1 2th of an 
inch wide, of hard- 
ened and thin steel, 
and fitted with a brass 
cap turned to a true cone, to receive the steel point on which 
it is to be balanced. The needle is then to be magnetized by 
drawing it across the face of a common horseshoe magnet three 
or four times. This needle is now balanced on a steel point 
3-i6ths of an inch high, soldered into a copper slip 2 in. long. 
Now glue on the needle a piece of glazed letter-paper, tapering 
from I in. to a point, and 2 in. long, at right angles to the 
magnetized needle. To limit the vibrations of the paper index, 
drive two copper 
pins in the base |- 
in. away each side 
of the index. Place ^ 
outside the coil a 
small magnet at 
right angles to the 
coil to keep the paper index in the middle of the two pins ; it will 
then appear as shown in the last diagram. 

Domestic Telegraph. — Cut four pieces of bright brass, 
and join two by soldering with a copper wire 4 in. long, as in 
fig. I. Then take the two other pieces and join them in the 
same manner by a copper wire 2 in. long, as in fig. 2. The 
wire must be soldered to one side, the two pieces to the left 
or to the right ; solder two more wires ; these wires are to 
go in the screw-cups of the battery. Drill a hole in the 
centre of each piece of brass, and countersink each hole 
so that the heads of the screws may be level ; now screw 
the four pieces on a piece of dry wood, as in fig. 3. The 
size of the brasses should be i in. wide, and i^ in. long. 
After the wires to convey the electricity are put up, and the 
telegraph instrument is at the top of the house, and the con- 



L/ 




330 



MAGNETISM, ELECTRICITY, 



veyance wires, two in number, are attached to each end of 
the coil of the instrument, the two ends at the bottom are 
to be attached to two small handles of brass, as in fig. 4. 
When a message is sent, the two handles are to be made to 
touch the right pair of brasses, if the index is meant to turn to 
the right ; if wanted to turn to the left, the handles are to be 



FlC . I 





Fic . 2 



FIC. 3 




FIC. 4. 



</ 



put on the left pair. Now perhaps when you put the handles 
on the right pair, the index will turn to the left ; you can 
remedy this by reversing the battery, i.e.^ put the positive wire 
where the negative was, and the negative where the positive 
was. By the adoption of what is called a code of signals, the 
deflections of a single index may be made to denote all the 



AND TELEGRAPHY, 331 

letters of the alphabet. The code for a single index instrument 
is shown in the following diagram, the number of deflections 

*A B C D E F 

\ W \\\ WW \, w wv 

G H I K L M 
N O P Q RS 

// /// //// vv y y/ 

T U V W X Y 

v// ^ y/ z y /y 4^ 

of the index to the right and left being made to indicate the 
letters under which the marks are placed. The deflections of 
the symbols for each letter commence in the direction of the 
short marks, and end with the long ones. Thus it will be seen, 
that to indicate the letter D, the index is deflected to the right 
once, then to the left once ; whilst two deflections, beginning 
with one to the left, and ending with one to the right, make the 
letter R. 



INDEX. 



The entries printed in Capitals indicate that several articles relating to 
the subject named will be found at the reference given. 



A B C Gas meter, 264. 
^olian harp, 228. 
Air-engine, 38. 
Air-pumps, 39. 
Alarums, 192. 

Alley's drilling machine, 28. 
Alloy for journal boxes, 23. 
Alphabetical dial telegraph, 326. 
Alum in safes, 250. 
Amalgam pad, 306. 
Aniline black varnish, 84, 
Aniline dyes, 266. 
Aquarium cementing, 81. 
Aquarium, fresh- water, 240. 
Aquarium fountain, 244, 
Axles, hardening, 9. 

Balance, chemical, 251. 
Balloons, fire, 294. 
Balloons, varnishing, 85. 
Bancroft's lard oil process, 255. 
Band-saws, brazing, 16. 
Barometer, simple, 78. 
Battery, constant, 301. 
Beams, cast-iron, breaking weight, 

98. 
Bell, electric, 311. 
Bevel-wheels, 59. 
Billiard balls, dyeing, 54. 
Bird-stufiing, 235. 



Bisulphide of tin, loi. 

Black for telescopes, &c., 74. 

Black Japan varnish, 84. 

Blacking, 261. 

Blast engine, 106. 

Bleaching ivory, 53. 

Bleaching powder, 268. 

Blow-pipe, 246, 247. 

Blow-pipe jointing, 92. 

Boats, model, steam propeller, 

128. 
Boilers, 105, 106, 127, 128. 
Bone manure, 262. 
Book marbling and sprinkling, 32, 

48. 
Boring, 31. 
Boring cork, 3. 
Boring-machine, 29. 
Bowls, cutting out, 53. 
Brakes, railway, 141. 
Brass, bronzing, 287. 
Brass, casting, 93. 
Brass, lacquering, 90. 
Brass, melting, 92. 
Brass, pickling, 93. 
Brass, silvering, 278. 
Brass-soldering, 91. 
Brass tubes, bending, 93. 
Brazing band-saws, 16. 
Brewer's pitch substitute, %%. 



334 



INDEX, 



Bright's electric clock, i6o. 
Bronzing, 284. 
Brooch stones, cutting, 33. 
Buckles in sheet-iron, 98. 

Camera lucida, 77. 

Camera obscura, 43. 

Cameras, dead black, 74. 

Candles, Roman, 290. 

Capstan-pumps, hydraulic, 41. 

Carrier, adjusting, 24. 

Carvings, wooden, protecting, 184. 

Case hardening, 96. 

Castings, brass, 93. 

Castings, shrinkings, loi. 

Cements and Glues, 79. 

Centre-bit, 35. 

Chemical balance, 251. 

Chemical Processes, &c., 246. 

Chimney cowls, 187, 188. 

Chimney lamp, 262. 

Chlorate of potash, 250. 

Chronometer escapement, 157. 

Chronometer oven, 169. 

Circle, diameter, 1 74. 

Cisterns, 194. 

Clarifying water, 254. 

Cleaning paint, 185. 

Cleaning pictures, 199. 

Cloak peg frame, 192. 

Clockmaking, 150. 

Clocks, electro-magnetic, 160, 309. 

Closet construction, 189. 

Coal gas, bisulphide of carbon, 261. 

Collodion filter, 211. 

Colour vehicle, 88. 

Colouring maps, 198. 

Columbia metal, 29. 

Combustion of oil rags, 250. 

Composition ornaments, 186, 282. 

Composition pictures, 222. 

Condenser, Rhumkorff, 306. 

Copal varnish, 85. 

Copper, bronzing, €86. 

Copper, coating, 94. 

Copper, electro-gilding, 274. 

Copper, silvering, 278. 

Copying ink, 259. 

Cork-boring, 3. 

Cork-springs, 42. 

Cotton photographs, 223. 



Cotton waste, 36. 
Cotton, waterproofing, 270. 
Cowls, chimney, 187, 188. 
Cmcibles of lime, 250. 
Curves, quickening, 5. 
Cutting glass, 175, 176. 
Cutting microscopic sections, 74. 
Cyanide of silver, 204. 
Cylinders, Geneva, 168. 

Damp on walls, 184. 

Dead-black for telescopes, &c., 74. 

Designs on glass, 177. 

Dials, sun, 171, 173. 

Diameter of circle, 1 74. 

Diamonds, polishing, 47. 

Distances, ascertaining, 6. 

Distances, rifle stadia, 148. 

Domestic telegraph, 329. 

Door spring, 185. 

Double photographs, 214. 

Dovetailing, 180. 

Drawing, 197. 

Drawing camera obscura, 43. 

Drawing on glass, 177. 

Drawing spirals, 4. 

Drawing varnishes, 84, 200. 

Drilling glass, 27. 

Drilling-machines, 3, 26, 28, 30, 

33. 
Drills, home made, 32. 
Drills, tempering, 9. 
Driving-straps, 47. 
Drowning : a rescue apparatus, 55. 
Dryers, 88. 
Dyes, 265. 
Dyeing ivory, 54. 

Earth batteries, 303. 

Edge tools, sharpening, 9. 

Electricity, &c., 295. 

Electric bell, 311. 

Electric clock, 160, 309. 

Electric railway signal, 135. 

Electro-gilding, 273, 274. 

Electrotyping, 270. 

Enamel, opaque, 178. 

Enamel for card photographs, 212. 

Engines, garden, 195. 

Engines* powers, 112. 

Engine, rotary, 102. 



INDEX, 



335 



Engravings, transferring to glass, 

177. 
Epicycloidal wheel, 175. 
Escapement, chronometer, 157. 
Escapement, double-roller, 159. 
Escapement, four-legged, 154. 
Escapement, verge, 150. 

Fan, fire, ii. 

Feathering float, 60. 

Feathers, ostrich, dyes, 266. 

Fictile ivory, 202. 

Files, renovating, 4. 

Filter, 190. 

Fire-arms, 148. 

Fire-balloons, 294. 

Fire-fan, 11. 

Fire-proofing textile fabrics, 270. 

Fireworks, 289. 

Fish in plaster moulds, 202. 

Fixing photographs, 217. 

Fixing prints, 211. 

Flower-pot battery, 301. 

Flowers dried in natural colours, 

239.. 
Focussing screen, 217. 
Fog signals, 138. 
Fountain for aquarium, 244. 
Freezing mixtures, 219. 
French weights and measures, I. 
French -polish, 86. 
Fret-saws, 14. 
Friction polish, 88. 
Frogs in plaster moulds, 202. 
Furnaces, smelting, loi. 

Galena and silver separation, 95. 
Galvanic battery, 317. 
Galvanometer, 311. 
Garden engine, 196, 197. 
Gas-blow-pipe, 249. 
Gas generator, 49. 
Gas, laughing, 251. 
Gas-meter, ABC, 264. 
Gas-pipes, soldering, 91. 
Gas-pipes, water in, 265. 
Geneva cylinders, 168. 
German silver, 100. 
German silver, polishing, 94. 
Giffard injector, 109. 
Gilding, 270. 



Glass, 175. 

Glass, cementing, 80. 

Glass, drawing on, 177. 

Glass, chimney breakage, 263. 

Glass-cutting, 175, 176. 

Glass-designs, 177. 

Glass, drilling, 27. 

Glass, gilding, 274. 

Glass-globes for magnifying glasses, 

218. 
Glass-plates, photographic cleaning, 

213. 
Glass, soluble, 179. 
Glass, transferring on, 177. 
Glass, varnishing, 84. 
Glazers for polishing metals, 97. 
Glues, 79. 
Gold, artificial, 95. 
Gold, dissolving, 95. 
Gold, lacquer, 89. 
Gold, mosaic, 284. 
Gold powder, 286. 
Gold size, 286. 

Governor's steam, 103, 107, 108. 
Grease, wheel, 148. 
Grinding pebbles, 33. 
Grinding lenses, 60. 
Grindstones, 12. 
Gum, postage stamp, 82. 
Gun-barrels, 149. 
Gun-barrels, bronzing, 287. 
Gun-cotton, 149. 
Gunpowder force, 149. 
Gauge for watch hands, 1 70. 
Gypsum, 201. 
Gyroscope, 68. 

Hair springs, reducing, 165. 

Handkerchiefs, photographic, 223. 

Hand-press, 21. 

Harness blacking, 261. 

Harp, ^olian, 228. 

Hat-peg frame, 192. 

Heights, measuring, 5. 

Hinges cutting, 56. 

Horology, 150. 

Hot-water pipes' cement, 82. 

House, 184. 

Huxley's tappet-pump, no. 

Hydraulic capstan pumps, 41. 

Hydraulic ram, '^'], 



336 



INDEX, 



Hydrogen lamp, 263. 
Hyposulphite of Ammonia, 207. 

Indelible pencil writing, 199. 

Indiarubber, 261, 262. 

Indiarubber cementing, 79. 

Incrustation in boilers, 105. 

Injector, Gififard, 109. 

Inks, 250. 

Inks for writing in relief on zinc, 

261. 
Inlaying with mother of pearl, 96. 
Insects for cases, 237. 
Instantaneous photography, 204. 
Instruments, miscellaneous, 3. 
Instruments, to keep from rust, 78. 
Insulation, telegraphic, 319. 
Iron, bronzing, 287. 
Iron, buckles in sheet, 98. 
Iron solders, 91. 
Iron stains, removing, 186. 
Ivory, bleaching, 53. 
Ivory, cleaning, 54. 
Ivory, dyeing, 54. 
Ivory, softening, 54. 
Ivory, fictile, 202. 

Joiners shooting boards, 184. 
Journal-boxes alloy, 23. 

Kaleidoscope, 57. 

Lacquers, 88. 

Lamp, chimney, 262. 

Lamp, hydrogen, 263. 

Lard oil, refining, 255. 

Lathe, rose bit, 4. 

Laughing gas, 251. 

Lead ores, working, 102. 

Leakage in smoke-box, 23. 

Leather, cementing, 79. 

Leather washers, 35. 

Leaves, skeletonising, 238. 

Lenses, cleaning, 22. 

Lenses, grinding, 60. 

Lenses' magnifying power, 65. 

Life-saving apparatus, 55. 

Lighting, 262. 

Light, artificial, for photography, 

215. 
Lime-crucible, 250. 



Lime-process in sugar extraction, 

.257. 
Lime-water, 256. 
Linen photographs, 223. 
Lock, magnetic, 19. 
Locomotives, 130. 
Lubricant, 250. 

Machines, boring, 29. 

Machines, drilling, 26, 27, 28, 30. 

Magic lantern photography, 220. 

Magnesium light, 215. 

Magnetism, 296. 

Magnetic Lock, 19. 

Mainsprings strength, 166. 

Manure, bone, 262. 

Map-colouring, 198. 

Marble imitating, 185. 

Marble, to remove stains, 188. 

Marbling books, 48. 

Marine propulsion, 60, 65. 

Matches without phosphorus, 249. 

Measures, French, i. 

Measuring distances, 6. 

Measuring heights, 5. 

Meek's watch hand gauge, 1 70. 

Mercurial pendulum, 163. 

Mercury, extracting, 100. 

Metals and metal- working, 92. 

Metals, cementing, 80. 

Metal glazers, 97. 

Metals, mixed, 99. 

Metric system, i. 

Micagraphy, 178. 

Microscope hints, 76. 

Microscope, wood sections, 74. 

Mirrors, silvering, 276, 278. 

Modelling, 200. 

Mosaic gold, 284. 

Mother of pearl, inlaying, 96. 

Mortar, waterproof, 184. 

Moulding plaster, 202. 

Moulding small objects, 202. 

Moulding, to prevent sand sticking, 

100. 
Music, ^olian harp, 228. 
Music, violins, 230. 

Nails, French and English, wire 

hand, 26. 
Needle, magnetised, 314. 



INDEX. 



337 



Negatives, reproducing, 222. 
Nitrate of potash, 253. 
Nitrate of silver, 209. 
Norton's well-pump, 45. 

Oil for watches, 171. 
Olive oil, refining, 254. 
Omnibus register, 50. 
Organ pipes, gilding, 283. 
Ornaments, composition for, 186. 
Ostrich feather dyes, 266. 
Oxychloride of zinc, 102. 

Paint, cleaning, 185. 
Painters' cream, 201. 
Painting on glass, 177, 178. 
Paintings, varnishing, 84. 
Paper bronzing, 289. 
Paper varnishing, 85. 
Paper for transfers, 197. 
Paper for tracing, 198. 
Papier-mache, 49. 
Paraffin waterproofing, 268. 
Parchment cleaning, 56. 
Parkes' plastic moulding, 202. 
Pebbles, grinding and polishing, 33. 
Peet's safety-valve, 1 1 7. 
Pencil drawings, preserving, 199. 
Pencil writing, indelible, 199. 
Pendulum, compensating, 157. 
Pendulum, mercurial, 163. 
Peroxide of nitrogen, 215. 
Perpetual motion, electric clock, 160. 
Petroleum stove, 255. 
Pewter, 99. 

Pharaoh's serpent, 295. 
Photography, 203. 
Photographometer, 206. 
Picture- cleaning, 199. 
Picture frames, gilding, 279. 
Picture frames, making, 281. 
Picture frames, in compo., orna- 
ments, 282. 
Picture frames, staining, 279. 
Pillar drilling-machine, 30. 
Pin, new style, 25. 
Pinion and rack, 174. 
Plant preserving, 258. 
Plaster of Paris, 201. 
Plaster casts, bronzing, 284. 
Plaster casts, varnishing, 203. 



Plate cleaning, 95. 
Plate soldering, 91. 
Plateholder, photographic, 220. 
Plating, 280. 

Plating skeleton leaves, 239. 
Plumbers' solder, 91. 
Polariscope, 77. 
Polish, French, 86. 
Polish, friction, 88. 
Polishing diamonds, 47. 
Polishing pebbles, 33. 
Porcelain cementing, 81. 
Postage-stamp gum, 82. 
Potash, chlorate, 250. 
Potash, nitrate, 253. 
Power of engines, 112. 
Preserving plants, 238. 
Preserving skins, 234. 
Prince Rupert's drops, 257. 
Printed cottons, washing, 268. 
Printers' ink, 258. 
Printing photographs, 214. 
Prints, fixing, 21 1. 
Prints, varnishing, 200. 
Processes, Miscellaneous, 3. 
Pumps, air, 39. 
Pump, tappet, no. 
Pump, deep well, 43. 
Putty for steam joints, %2i' 
Pyrotechny, 289. 

Quickening curves, 5. 

Radii-drawing to inaccessible cen- 
tres, 48. 
Rags oily combustion, 250. 
Railways and locomotives, 130. 
Rain-water, storing, 195. 
Ram, hydraulic, 37. 
Ratchet wheels, 52. 
Registering machine for 'buses, 52. 
Retouching photographs, 221. 
Reversing motion in engines, 125. 
Rhumkorff condenser, 306. 
Rick cloths, waterproofing, 270. 
Rifle stadia for distances, 148. 
Rock- drilling, 27. 
Rockets, 291, 292, 293. 
Roman candles, 290. 
Rose-bit for lathe, 4. 
Rotary engine, 102. 

Y 



338 



INDEX. 



Rotating magnet, 313. 

Rupert drops, 25. 

Rust on instruments, 78. 

Sackholder, 46. 

Safes, alum in, 250. 

Safety-valves, 112, 117, 118, 120, 

121. 
Saw benches, 13. 
Sawing machine, 18. 
Saws, band, brazing, 16. 
Saws, fret, 14. 
Screw-driver, 20. 
Screw-propeller, 67. 
Sealing wax, 256. 
Semaphores, 131. 
Sharpening edge tools, 9. 
Shooting boai-ds for joiners, 184. 
Shrinkings of castings, loi. 
Siemen and Halske's insulator, 

321. 
Signals, fog, 138. 
Signals, railway, 130, 135, 139. 
Silk, blue, dye, 265, 266. 
Silk photographs, 21 1. 
Silver cyanide, 204. 
Silver dial cleaning, 168. 
Silver in photography, 207, 208, 

209. 
Silver, hardness, 94. 
Silver, separating from galena, 95. 
Silver, soldering, 91. 
Silver, German, 100. 
Silvering, brass, 278. 
Silvering, copper, 178. 
Silvering, imitation, 283. 
Silvering globes, &c., 276. 
Silvering mirrors, 278. 
Skates, wheeled, 50. 
Skeleton leaves, 238. 
Skins, preserving, 234. 
Slide-valve, 119, 122, 126. 
Smelting furnace, loi. 
Smoke-box leakage, 23. 
Smoky chimney, cowl for, 188. 
Solders and soldering, 90. 
Soluble glass, 179. 
Speculum metal, 100. 
Spirals, 4, 5. 

Spirit blow-pipes, 246, 247. 
Spring for doors, 185. 



Springs, cork, 42. 
Sprinkling book-edges, 32. 
Stains of nitrate of silver, 217. 
Stains on marble, to remove, 188. 
Staining wood, 182. 
Steam engine, 102. 
Steam -joints, cementing, 82. 
Steam-pipes, cementing, 82. 
Steam-propeller for model boats, 

128. 
Steel, bronzing, 287. 
Steel, gilding, 273. 
Steel, polished, preserving, 97. 
Steel, soldering, 91. 
Steel surfaces, preservation, 98. 
Steel, tempering, 10. 
Steel welding composition, 96. 
Stencil-plates, 198. 
Stereotyping, paper process, 25. 
Stone cementing, 80. 
Straps, driving, 47. 
Straw, to colour black, 267. 
Stud-box and wrench, 23. 
Studio photographic design, 224. 
Stuffing birds, 234. 
Sugar extraction, lime process, 257. 
Sulphate of iron preservation, 99. 
Sun-dial, 171, 173. 
Superheater and safety valve, 118. 
Swann's safety valve, 113. 
Syphon, 38. 

T-square, protracting, 10. 

Tappet-pump, no. 

Taps, tempering, 9. 

Taxidermy, 234. 

Telegraphy, 314. 

Telescopes, dead black, 74. 

Telescopes' stand, 73. 

Telescopes, making, 71. 

Tempera, 186. 

Tempering drills and taps, 9. 

Tempering steel, 10. 

Tent, photographic, 227, 228. 

Textile fabrics, fireproof, 270. 

Tin bisulphide, loi. 

Tin lacquer, 89. 

Tinning, loi. 

Tinware, solder, 91. 

Tissue-paper, oiling, 198. 

Titanium, German, 99. 



INDEX. 



339 



Titanium, Spanish, 99. 
Tools, miscellaneous, 3. 
Tools, hardening and tempering, 
II. 

Tools, sharpening, 9. 
Tortoiseshell, polishing, 56. 
Tracing-paper, 198. 
Tracings, cement, 80. 
Tramway locomotives, 146. 
Transferring on glass, 177. 
Transfer paper, 197. 
Tube-well pump, 44. 
Type metal, 99. 

Valves, safety, 112. 

Valve, slide, 122. 

Varnishes, 83. 

Varnishes for photographs, 216. 

Varnishes for prints and drawings, 

200. 
Varnishing plaster casts, 203. 
Vegetables in plaster moulds, 202. 
Vellum cleaning, 55. 
Vehicle for colour, Z%. 
Ventilation, 190. 
Verge escapements, 150. 
Vibration, musical, 234. 
Vinegar, anti-pestilential, 186. 
Violins, home-made, 230. 
Violin tools, 231. 
Violins, varnishing, 87. 
Vulcanised india-rubber, 262. 

Walls, damp, 184. 
Walls in tempera, 186. 
Washers, leather, 35. 
Washing printed cottons, 268. 



Waste cotton, 36. 

Watchmaking, 150. 

Water, clarifying, impure, 254. 

Water storing, 195. 

Waterproof enamel for photographs, 

212. 
Waterproof mortar, 184. 
Waterproofing, 268. 
Water-wheel, 36. 
Weapons, hardening and tempering, 

II. 
Weather-glass, 78. 
Weights and Measures, i. 
Welding composition for steel, 96. 
Well-pumps, 43, 44. 
Wheeled skates, 50. 
Wheel, epicycloidal, 175. 
Wheel, feathering float, 60. 
Wheel grease, 148. 
Wheels, bevel, 59. 
White metal, 96, 99. 
Wood, bronzing, 288. 
Wood carvings, protecting, 184. 
Wood cementing, 80. 
Wood microscopic sections, 74. 
Woodstaining, 182. 
Woods, strength of, 179. 
Wood, varnishing, 86. 
Wood, washed, 179. 
Woodbury process, 214. 
Woollens' dyes, 266. 
Wrench, 23, 
Writing in pencil indelible, 199. 

Zinc, oxy chloride, 102. 

Zinc perforated, varnishing, 86. 

Zinc, writing in, 261. 



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Weisbaoh^s Mechanics. 

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A MANUAL OF THE MECHANICS OF ENGINEEEING, 
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lEON TEUSS BEIDGES EOE EAILEOADS. The Method of 
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ILONG AND SHORT SPAN RAILWAY BRIDGES. By Johk 
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Campin on Iron Roofs. 

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aiid. plates of Eoofs lately executed. 

" The mathematical formulas are of an elementary kind, and the process 
admits of an easy extension so as to embrace the prominent varieties of iron 
truss bridges. The treatise, though of a practical scientific character, may bo 
easily mastered by any one familiar with elementary mechanics and plane 
tiigonometry." 

Holley^s Railway Practice. 

1 vol. folio. Cloth. $12.00. 

AMEEIOAN AND EUEOPEAN EAILWAT PEAOTICE, in 

the Economical Generation of Steam, including the materials 
and construction of Coal-burning Boilers, Combustion, the Varia- 
ble Blast, Vaporization, Circulation, Super-heating, Supplying 
and Heating Feed- water, &c., and the adaptation of Wood and 
Coke-buriiing Engines to Coal-burning ; and in Permanent V/ay, 
including Eoad-bed, Sleepers, Eails, Joint Fastenings, Street 
Eailways, «&c., &c. By Alexandek L. Holley, B. P. With 77 
lithographed plates. 

*' This is an elaborate treatise by one of our ablest civil engineers, on the con- 
struction and use of locomotives, with a few chapters on the building of E,ail- 
roeds. ^ ^ ^ j\,ll these subjects are treated by the author, who is i 
first-claas railroad engineer, in both an intelligent and intelligible manner. Tho 
facts and ideas are well arranged, and presented in a clear and siniple style, 
accompanied by beautiful engravings, and we presume the work will be regard' 
ed as indispensable by all who are interested in a knowledge of the construc- 
tion of railroads and rolling stock, or the working of locomotives." — Scientific 
American. 



8 SCIENTIFIC BOOKS PUBLISHED BY 

Henricfs Skeleton Strnctures. 

8vo. Cloth. $1.50. 

SKELETON STEUCTUEES, especially in their Application to 
the building of Steel and Iron Bridges. By Olaus ^enpwICi. 
With folding plates and diagrams. 

By presenting these general examinations on Skeleton Structures, ^vith 
particular application for Suspended Bridges, to Engineers, I venture to ex- 
press the hope that they will receive these theoretical results with some confi- 
dence, even although an opportunity is wanting to compare tiiem with practi- 
cal results. O. H. 



Useful Information for Railway Men. 

Pocket form. Morocco, gilt, $2.00. 

Compiled by W. G. Haiviilton, Engineer. Sixth edition, revised 
and enlarged. 570 pages. 

" It embodies many valuable formulce and recipes useful for railway men, 
and, indeed, for almost every class of persons in the world. The * informa- 
tion ' comprises some valuable formulse and rules for the construction of 
boilers and engines, masonry, properties of steel and iron, and the strength, 
of materials generally." — Eailroad Oazette, Chicago, 



Holley's Ordnance and Armor. 

493 Engravings. Half Roan, $10.00. Half Russia, $12.00. 

A TEEATISE ON OEDNANCE AND AEMOE— Embracing 
Descriptions, Discussions, a^nd Professional Opinions concerning 
the Material, Eabricatiost, Eequirements, Capabilities, and En- 
durance of European and American Guns, for Naval, Sea Coast, 
and Iron-clad Warfare, and their Eifling, Projectiles, and 
BiiEEcn-LoADiNG ; also, Eesults of Experiments against Armor, 
from Official Eecords, with an Appendix referring to Gun-Cotton, 
Hooped Guns, etc., etc. By Alexander L. IIolley, B. P. 948 
pages, 493 Engravings, and 147 Tables of Eesults, etc. 



1). VAN NOSTRAJSTD, 9 



Kirki^ood on Filtration, 

4to. Cloth. $15.00. 

EEPOET ON THE FILTRATION OF EIVER WATEES, for 

tlie Supply of Cities, as practised in Europe, made to the Board 
of "Water Commissioners of the City of St. Louis. Bj James P. 
KiKKWooD. Illustrated by 30 double-plate engravings. 

Contents. — Beport on ^Filtration — London "Works, General — Chelsea 
"Water Works and Filters — Lambeth Water Works and Filters — South wark 
and Vauxhall "Water Works and Filters — Grand Junction Water Works and 
Filters — West Middlesex Water Yv^orks and Filters — Ne-w Hiver Y/ater 
"Works and Filters — East London Y»^ater Works and Filters — Leicester Water 
Works and Filters — York Water Works and Filters — Liverpool Water Y/orks 
and Filters — Edinburgh Water Works and Filters — Dublin Water Works 
and Filters — Perth Y/ater Works and Filtering Gallery — Berlin Water 
"Works and Filters — Hamburg Water Works and Eeservoirs — Altona Water 
"Works and Filters — Tours Water Works and Filtering Canal — Angers Water 
Yi^orks and Filtering Galleries — Nantes Water Y^orks and Filters — Lyons 
Water Works and Filtering Galleries — Toulouse Water Works and Filtering 
Galleries — Marseilles Water Works and Filters — Genoa Water Works and 
Filtering Galleries — Leghorn Yf ater Works and Cisterns — Wakefield Water 
Works and Filters — Appendix. 



Tunner on Roll-Turning. 

1 vol. 8vo. and 1 vol. plates. $10.00. 

A TEEATISE ON EOLL-TUENING FOE THE MANUFAC^ 
TUEE OF lEON. By Peter Tunnee. Translated and adapted. 
By JoKN- B. Peause, of the Pennsylvania Steel Y/orks. With 
numerous wood-cuts, 8vo., togetlier with a foho atlas of 10 litho- 
graphed plates of Eolls, Measurements, &c. 

" We commend this book as a clear, elaborate, and practical treatise upon 
the department of iron manufacturing operations to which it is devoted. 
The Writer states in his preface, that for twenty-five years he has felt the 
necessity of such a work, and has evidently brought to its preparation the 
fruits of experience, a painstaking regard for accuracy of statement, and a 
desire to furnish information in a style readily understood. The book should 
be in the hands of every one interested, either in the general practice of 
mechanical engineering, or the special branch of manufacturing operations to 
which the work relates.*' — American Artisan. 



10 SCIENTIFIC BOOKS PUBLISHED BY 

Jacob on Storage Reservoirs. 

18mo. Boards 50 cts. 

THE DESIGNING AND CONSTEUCTION OF STORAGE 
EESERVOIKS. By Ahtiiur Jacob, B. A. With tables and ' 
wood-cuts representing sections, etc. 



Hewson on Embankments. 

8vo. Clotli. $2.00. 

PEINCIPLES AND PRACTICE OF EMBANKING LANDS 

from River Floods, as applied to the Levees of the Mississippi. 
By William Hewson, Civil Engineer. 

" This is a valuable treatise on the principles and practice of embanking' 
lands from river floods, as applied to the Levees of the Mississippi, by a highly- 
intelligent and experienced engineer. The author says it is a first attempt 
to reduce to order and to rule the design, execution, and measurement of the 
Levees of the Mississippi. It is a most useful and needed contribution to 
scientific literature. — Philadelphia Evening Journal. 



Griiner on Steel. 

8vo. Cloth. $3.50. 

THE MANUFACTURE OF STEEL. By M. L. Gruner, trans- 
lated from the French. By Lenox Smith, A. M., E. M., with an 
appendix on the Bessemer Process in the United States, by the 
translator. Illustrated by lithographed drawings and wood-cuts. 

" The purpose of the work is to present a careful, elaborate, and at the 
same time practical examination into the physical properties of steel, as well 
as a description of the new processes and mechanical appliances for its manufac- 
ture. The information which it contains, gathered from many trustworthy 
sources, will be found of much value to the American steel manufacturer, 
who may thus acquaint himself with the results of careful and elaborate ex- 
periments in other countries, and better prepare himself for successful com- 
petition in this important industry with foreign makers. The fact that thia 
volume is from the pen of one of the ablest metallurgists of the present day, 
oanuot fail, we think, to secure for it a favorable consideration. — Iron Age, 



J). VAN' N'OSTBAN'D. 11 

> ' ■■-■ — ~— — — — ' — — — 

Banerman on Iron. 

12nio. Cloth. $2.00. 

TEEATISE ON THE METALLUE&Y OF lEON. Contain- 
ing outlines of the History of Iron Manufacture, methods of 
Assay, and analysis of Iron Ores, processes of manufacture of 
Iron and Steel, etc., etc. By H. BAUEiiMAiSr. Eirst American 
edition. Eevised and enlarged, with, an appendix on the Martin 
Process for making Steel, from the report of Abram S. Hewitt. 

' Illustrated "^th numerous wood engravings. 
*-^ 

** This is an important addition to the stock of technical ^orks published in 
this country. It embodies the latest facts, discoveries, and processes con- 
nected with the maiiufacture of iron and steel, and should be in the hands of 
overy person interested in the subject, as well as in all technical and seientifio 
libraries." — Scientific American, 



Link and Valve Motions, by W, S. 

ATichincloss. 

Sixth Edition. 8vo. Cloth.- $3.00. 

APPLICATION OF THE SLIDE VALVE and Link Motion to 
Stationary, Portable, Locomotive and Marine Engines, witli now 
and simple metliods for proportioning the parts. By "William 
S. AucHiNCLOss, Civil and Mechanical Engineer. Designed as 
a hand-book for Mechanical Engineers, Master Mechanics, 
Draughtsmen and Students of Steam Engineering. All dimen- 
sions of the valve are found with the greatest ease by means of 
a Printed Scale, and proportions gf the link determined without 
the assistance of a model. Illustrated by 37 wood-cuts and 2 1 
lithographic plates, together with a copperplate engraving of tho 
Travel Scale. 

All the matters "we have mentioned are treated with a clearness and absence 
of unnecessary verbiage which renders the work a peculiarly valuable one. 
The Travel Scale only requires to be known tx) be appreciated. Mr. A. writes 
so ably on his subject, we wish he had written more. London En* 
gineering, 

"We have never opened a work relating to steam which seemed to us better 
calculated to give an intelligent mind a clear understanding of the depart-* 
ment it discusses. — Scientifixi American, 



112 SCIENTIFIC BOOKS PUBLISHED BY 

'^—— — ■ ■ — V 

Slide Valve by Eccentrics, by Prof. 
O. W. MacCord. 

4to. Illustrated. Cloth, $4.00. 

A PEACTICAL TEEATI8E ON THE SLIDE YALYE BY 
ECCENTEICS, examining by methods, the action of the Eccen- 
tric upon the Slide Yalve, and explaining the practical proces- 
se'fe of laying out the movements, adapting the valve for its 
various duties in the steam-engine. For the use of Engineers, 
Draughtsmen, Machinists, and Students of valve motions in 
general. By 0. "W. MacOoed, A. M., Professor of Mechanical 
Drawing, Stevens' Institute of Technology, Hoboken, N J. 



Stillman's Steam-Engine Indicator. 

12mo. Clotfc. $1.00. 

THE STEAM-ENGINE INDICATOE, and the Improved Mano- 
meter Steam and Yacuum Gauges ; their utility and application 
By Paul Stillman. New edition. 



Bacon's Steam-Engine Indicator. 

12mo. Cloth. $1.00. Hor. $1.50. 

A TEEATISE ON THE EICHAEDS STEAM-ENGINE IN- 
DICATOE, with directions for its use. By Chaeles T. Porter. 
Eevised, with notes and large additions as developed by Amer- 
ican Practice, with an Appendix: containing useful formulae and 
rules for Engineers. By F. W. Bacon, M. E., Member of thn 
American Society of Civil Engineers. Illustrated. Second Edition 

In this work, Mr. Porter's book has been taken as the basis, but Mr. Bacon 
has adapted it to American Practice, and has conferred a great boon on 
American Engineers. — Artimn. 



Steam Boiler Explosions. 

18mo. Boards. 50 cts. 
STEAM BOILER EXPLOSIOi^S. By ZEiiAir Colbutix. 

*' It is full of practical information, and serves to show in a most marked 
manner how very little one's knowledge upon the subject has advanced during 
the past ten years."— iV. Y, Times. 



I), VAN JsfOSTRAlTD, 13 

Gillmore^s Limes and Cements. 

Fifth Edition, Jievisel and Unlargd. 

8vo. Cloth. $4.00. 

PEACTICAL TEEATISE ON LIMES, HYDEAULIC CE- 
MENTS, AND MOETAES. Papers on Practical Engineering:, 
U. S. Engineer Department, No. 9, containing Eeports of 
numerous experiments conductod in New York City, during the 

years 1858 to 1861, inclusive. By Q. A. (tILLMoke, Lt-Col. 

U. S. Corps of Engineers, Brevet Major-General U. S. Army. 

With numerous illustrations. 

" This ^ork contains a record of certain experiments and researches made 
under the authority of the Engineer Bureau of the War Department from 
1858 to 1861, upon the various hydraulic cements of the United States, and 
the materials for their manufacture. The experiments were carefully made, 
and are well reported and compiled. ' — Journal Franklin Institute, 



Qillmore's Coignet Beton. 

Svo. Cloth. §2.50. 

COIGNET BETON AND OTHEE AETIFICIAL STONE. By 
Q. A. GiLLMORE, Lt.-Col. U. S Corps of Engineei^, Brevet 
Major-General U. S. Army. 9 Plates, Views, etc. 

This work describes with considerable minuteness of detail the several kinds 
of artificial stone in most general use in Europe and now beginning to be 
introduced in the United States, discusses their properties, relative merits, 

and cost, and describes the materials of which they are composed 

The subject is one of special and growing interest, and we commend the work, 
embodying as it does the matured opinions of an experienced engineer and 
expert. 



Gillmore on Roads. 

13mo. Cloth. In Press. 

A,.PRAOTIOAL TREATISE ON THE CONSTEUCTIOlSr 
OF ROADS, STREET8, AND PAVEMENTS. By Q. A. 
GiLLMORE, Lt.-Col. U. S. Corps of Engineers, Brevet Major- 



14 BCIEJSTTIFIC BOOKS PUBLISHED BY 



Williamson on the Barometer. 

4to. Clotli. $15.00. 
ON THE USE OF THE BAEOMETEE, ON SUEYEYS AND 
EECONNAISSANCES. Part I. Meteorology in its Connec- 
tion with Hypsometiy. Part 11. Barometric Hypsometry. By 
E. S. Williamson, Bvt. Lieut.-Col. U. S. A., ]\Iajor Corps of 
Engineers. With Illustrative Tables and Engravings. Paper 
Ko. 15, Professional Papers, Corps of Engineers. 

" San Fhancisco, Cal., Feb, 27, 1867. 
" Gen. A. A. Humphreys, Chief of Engineers, U. S. Army : 

" General, — I have the honor to submit to you, in the following pages, the 
results of my investigations in meteorology and hypsometry, made with the 
view of ascertaining how far the barometer can be used as a reliable instru- 
ment for determining altitudes on extended lines of survey and reconnais- 
sances. These investigations have occupied the leisure permitted me from my 
professional duties during the last ten years, and I hope the results will bo 
deemed of sufficient value to have a place assigned them among the printed 
professional papers of the United States Corps of Engineers. 
" Very respectfully, your obedient servant, 

''R. S. WILLIAMSOK, 
"Bvt. Lt.-Col. U. S. A., Major Corps of U. S. Engineers." 



Yon Cottars Ore Deposits. 

8vo. Cloth. §4.00. 
TEEATISE ON OEE DEPOSITS. By Bernhaed Von Gotta, 
Professor of Geology in the Eoyal School of Mines, Ereidberg, 
Saxony. Translated from the second German edition, by 
Eeedeeick Peime, Jr., Mining Engineer, and revised by the 
author, with numerous illustrations. 

" Prof. Von Cotta of the Freiberg School of Mines, is the author of tlie 
best modern treatise on ore deposits, and wo are heartily glad that this ad- 
mirable work has been translated and published in this country. The trans- 
lator, Mr. Frederick Prime, Jr., a graduate of Freiberg, has had in his work 
the great advantage of a revision by the author himself, who declares in a 
prefatory note that this may bo considered as a new edition (the third) of his 
own book. 

" It is a timely and welcome contribution to the literature of mining in 
this country, and we are grateful to the translator for his enterprise and good 
judgment in undertaking its preparation ; while we recognize with equal cor- 
diality the liberality of tho author in granting both permission and assist- 
ance." — Extract from llcvicw in Engineer Incj ami Mining Jouriuil. 



D, VAN NOSTRANJ). 15 

Plattner^s Blo^w^-Pipe Analysis. 

Second edition. Revised. 8vo. Cloth. $7.50. 

PLATTNEE'S MANUAL OF QUALITATIVE AND QUAN- 
TITATIVE ANALYSIS WITH THE BLOW-PIPE. Prom 
the last German edition Eevised and enlarged. By Prof. Th. 
EiCHTEPt, of the Eoyal Saxon Mining Academy. Translated by 
Prof. H. B. Cornwall, Assistant in the Colnmbia School of 
Mines, New York ; assisted by John H. Caswell. Illustrated 
with eighty-seven wood-cuts and one Lithographic Plate. 560 
pages. 

" Plattner's celebrated work has long been recognized as the only complete 
book on Blow-Pipe Analysis. The fourth German edition, edited by Prof. 
B-ichter, fully sustains the reputation which the earlier editions acquired dur- 
ing the lifetime of the author, and it is a source of great satisfaction to us to 
know that Prof. Richter has co-operated with the translator in issuing the 
American edition of the work, which is in fact a fifth edition of the original 
work, being far more complete than the last German edition." — SilUman^s 
Journal. 

There is nothing so complete to be found in the English language. Platt- 
ner's book is not a mere pocket edition ; it is intended as a comprehensive guide 
to all that is at present known on the blow-pipe, and as such is really indis- 
pensable to teachers and advanced pupils. 

*' Mr. Comwairs edition is something more than a translation, as it contains 
many corrections, emendations and additions not to be found in the original. 
It is a decided improvement on the work in its German dress." — Journal of 
Applied Chemistry, 



Egleston's Mineralogye 

8vo. Illustrated with 34 Lithographic Plates. Cloth. $450. 

LECTUEES ON DESCEIPTIVE MINEEALOGY, DeHvered 
at the School of Mines, Columbia College. By PEOFEssoii T. 
Egleston. 

These lectures are what their title indicates, the lectures on Mineralogy 
delivered at the School of Mines of Columbia College. They have been 
printed for the students, in order that more time might be given to the vari- 
ous methods of examining and determining minerals. The second part has 
only been printed. The first part, comprising crystallography and physical 
mineralogy, will be printed at some future time. 



iG sciejsttific docks publuhed by 
Pynchon^s Chemical Physics, 

New Edition. Mevised and Enlarged, 
Crown 8vo. Cloth. $3.00. 

INTEODUCTION TO CHEMICAL PHYSICS, Designed for the 
Use of Academies, Colleges, and Higli Schools. Illustrated witli 
numerous engravings, and containing copious experiments with 
directions for preparing them. By Tno:MAS E-uggles Pyxcho:^-, 
M.A., Professor of Chemistry and the Natural Sciences, Trinity 
College, Hartford. 

Hitherto, no TTork suitable for general use, treating of all these subjects 
•within the limits of a single volume, could bo found ; consequently the atten- 
tion they have received has not been at all proportionate to their importance. 
It is believed that a book containing so much valuable information within so 
small a compass, cannot fail to meet with a ready sale among all intelligent 
persons, while Professional men. Physicians, Medical Students, Photogra];)h- 
ers, Telegraphers, Engineers, and Artisans generally, will find it special!/ 
valuable, if not nearly indispensable, as a book of reference. 

" We strongly recommend this able treatise to our readers as the first 
•work ever published on the subject free from perplexing technicalities. In 
style it is pure, in description graphic, and its typographical appearance is 
artistic. It is altogether a most excellent work.'* — Edeciic Medical JournaL 

" It treats fully of Photography, Telegraphy, Steam Engines, and the 
various applications of Electricity. In short, it is a carefully prepared 
volume, abreast "with the latest scientific discoveries and inventions.' — Hart- 
ford CouranL 

Plympton's Blow-Pipe Analysis. 

12mo. Cloth. $150. 

THE BLOW-PIPE : A Guide to Its Use in the Determination 
of Salts and Minerals. Compiled from various sources, by 
George W. PlympTon, C.E., A.M., Professor of Physical 
Science in tlie Polytechnic Institute, Brooklyn, N. Y. 

" This manual probably has no superior in the English language as a text- 
book for beginners, or as a guide to the student working without a teacher. 
To the latter many illustrations of the utensils and apparatus required in 
using the blow-pipe, as well as the fully illustrated description of the blow- 
pipe flame, will be especially serviceable.*' — New York 2'eaclter, 



D. VAN' NOHTRARB. 



lire's Dictionary* 

Siocth Edition. 

London, 1872. 
3 vols. Half Kussia, $32.50. 

DICTIONAEY OF AETS, MANUFACTUEES, AND MINES. 
By Andeew Uke, M.D. Sixth, edition. Edited by Eobeet Hunt, 
F.E.S., greatly enlarged and rewritten. 



G-ases in Coal Mines. 

18mo. Boards. 50 cts. 

A PRACTICAL TREATISE ON THE GASES MET V/ITH 
IN COAL MINES. By the late J. J. Atkikso^-, Govern- 
ment Inspector of Mines for the County of Durham, England. 



Watt's Dictionary of Chemistry. 

Supple^nentary Volume. 

8vo. Cloth. $9.00. 

This volume brings the Record of Chemical Discovery down to the end of 
the year 18G9, including* also several additions to, and corrections of, former 
results which have appeared in 1870 and 1871. 

*^*'^ Complete Sets of the Work, Kew and Heviaed edition, including above 
supplement. G vols. 8vo. Cloth. $62.00. 



Rammelsberg^s Chemical Analysis. 

8vo. Cloth. $2.25. 

GUIDE TO A COUESE OF QUANTITATIVE CHEMICAL 
ANALYSIS, ESPECIALLY OF MINERALS AND FUR- 
NACE PRODUCTS. Illustrated by Examples. By C. F. 
Eammelsbekg. Translated by J. Towler, M.D. 

This v/ork has been translated, and is now published expressly for those 
students in chemistry whose time and other studies in colleges do not permit 
them to enter upon the more elaborate and expensive treatises of Fresenius 
and others. It la the condensed labor of a master in chemistry and of a prac- 
tical analyst. 



18 SCIENTIFIC BOOKS PUBLISHED BY 

Eliot and Storer's Qualitative 
Oheinical Analysis. 

Ketv Edition, Mevised* 

12mo. Illustrated. Cloth. $1.50. 

A COMPENDIOUS MANUAL OF QUALITATIVE CHEMI^ 
CAL ANALYSIS. By Chaeles AV. Eliot and ErankH. Stoher. 
Eevised with the Cooperation of the Authors, by William Ivir- 
LEY Nichols, Professor of Chemistry in the Massachusetts Insti- 
tute of Technology. 

" This Manual has great merits as a practical introduction to the science 
and the art of which it treats. It contains enough of the theory and practice 
of qualitative analysis, ** in the wet way,'' to bring out all the reasoning in- 
volved in the science, and to present clearly to the student the most approved 
methods of the art. It is specially adapted for exercises and experiments in 
the laboratory; and yet its classifications and manner of treatment are so 
systematic and logical throughout, as to adapt it in a high degree to that 
higher class of students generally who desire an accurate knowledge of the 
practical methods of arriving at scientific facts." — Lutheran Obserwr, 

" We wish every academical class in the land could have the benefit of the 
fifty exercises of two hours each necessary to master this book. Chemistry 
would cease to be a mere matter of memory, and become a pleasant experi- 
mental and intellectual recreation. "We heartily commend this little volume 
to the notice of those teachers who believe in using the sciences as means of 
mental discipline." — College CouranL 



Craig's Decimal System. 

Square 32mo. Limp. 50c. 

WEIGHTS AND MEASUEES. An Account of the Decimal 
System, with Tables of Conversion for Commercial and Scientific 
Uses. By B. E. Craig, M. D. 

" The most lucid, accurate, and useful of all the hand-books on this subject 
that we have yet seen. It gives forty-seven tables of comparison between the 
English and French denominations of length, area, capacity, weight, and the 
Centigrade and Fahrenheit thermometers, with clear instructions how to use 
them ; and to this practical portion, v/hich helps to make the transition as 
easy as possible, is prefixed a scientific explanation of the errors in the metric 
system, and how they may be corrected in the laboratory." — Nation, 



D, VAN NOSTRAND, 19 



Nugent on Optics. 

12mo. Cloth. $2.00 

TEEATISE ON OPTICS ; or, Light and Sight, theoretically and 
practically treated ; ^\ith the application to Fine Art and Indus- 
trial Pursuits. By E. Nugent. With one hundred and three 
illustrations. 

" This book is of a practical rather than a theoretical kind, and is de- 
signed to afford accurate and complete information to all interested in appli- 
cations of the science." — Round Table. 



Barnard's Metric System, 

8vo. Brown cloth. $3.00. 

THE METEIO SYSTEM OF WEIGHTS AND MEASURES. 

An Address delivered before the Convocation of the University of 
the State of New York, at Albany, August, 1871. By Fredeiuck 
A. P. BAENAiiD, President of Columbia College, New York City. 
Second edition from the Pevised edition printed for the Trustees 
of Columbia College. Tinted paper. 

" It ig the best summary of the arguments in favor of the metric weights 
and measures with which we are acquainted, not only because it contains in 
small space the leading facts of the case, but because it puts the advocacy of 
that system on the only tenable grounds, namely, the great convenience of a 
decimal notation of weight and measure as well as money, the value of inter- 
national uniformity in the matter, and the fact that this metric system is 
adopted an(k in general use by the majority of civilized nations." — The Nation'^ 



Butler on Ventilation, 

18mo. Boards. 50 cts. 

VENTILATION OP BUILDINGS. By W. F. Butler. 

Illustrated. 

" As death hj insensible suffocation is one of the prominent causes which 
swell oar bills of mortality, we commend this book to the attention of philan- 
thropists as well as to architects." — Boston Globe. 



20 SCIENTIFIC BOOKS PUBLISHED BY 

Harrison's Mechanic's Tool-Book. 

12mo. Cloth. $1.50. 

MECHANIC'S TOOL BOOK, with practical rules and suggestions, 
for the use of Machinists, Iron Workers, and others. By W. B. 
Harrison, Associate Editor of the ^^ American Artisan." Illustra- 
ted with 4-1: engravings. 

" This work is specially adapted to meet the wants of Machinists and work- 
ers in iron generally. It is made np of the work-day experience of an intelli- 
gent and ingenious mechanic, who had the faculty of adapting tools to various 
purposes. The practicability of his plans and suggestions are made apparent 
even to the unpractised eye by a series of well-executed wood engravings." — 
Pliiladclplda Inquirer, 

Pope^s Modern Practice of tlie Elec- 
tric Telegraph. 

Ninth Edition. 8vo. Cloth $2.00. 

A Hand-book for Electricians and Operators. By Er^itk L. Pope. 
Seventh edition. Eerised and enlarged, and fully illustrated. 

Extract from Letter of Prof. Morse. 

" I have had time only cursorily to examine its contents, but this examina- 
tion has resulted in great gratification, especially at the fairness and unpre- 
judiced tone of your whole work. 

" Your illustrated diagrams are admirable and beautifully executed. 

" I think all your instructions in the use of the telegraph apparatus judi- 
cious and correct, and I most cordially wish you success." 

Extract from Letter of Prof. G. W. Hough, of the Dudley Ohservatorij. 

" There is no other work of this kind in the English language that con- 
tains in so small a compass so much practical information in the application 
of galvanic electricity to telegraphy. It should be in the hands of every one 
interested in telegraphy, or the use of Batteries for other purposes." 



Morse's Telegraphic Apparatus. 

lUusijrated. 8vo. Cloth. $3.00. 

EXAMINATION OF THE TELEGEAPHIC APPAEATUS 
AND THE PEOCESSES IN TELEGAPIIY. By Samuel F. 
B. Mouse, LL.D., United States Commissioner Paris Universal 
Exposition, 1867. 



D. VAN' N'OSTEAN'D. 21 

^"^ ^ . 

Sabine^s History of the Teiegrapli. 

12iiio. Cloth. $1.25. 

HISTOEY AND PEOGEESS OF THE ELECTEIO TELE- 
GEAPH, witli Descriptions of some of the Apparatus. By 
EoBEET Sa.bi2«^e, C. E. Second edition, with additions. 

Contents. — I. Early Observations of Electrical Phenomena. II. Tele- 
graphs by Erictional Electricity. III. Telegraphs by Voltaic Electricity. 
IV. Telegraphs by Electro-Magnetism and Magneto-Electricity. V. Tele- 
graphs now in use. VI- Overhead Lines. VII. Submarine Telegraph Lines. 
Vm. Underground Telegraphs. IX. Atmospheric Electricity. 



Haskins' Galvanometer. 

Pocket form. Illustrated. Morocco tucks. $2.00. 

THE GALVANOMETEE, AND ITS USES ; a Manual for 
Electricians and Students. By 0. H. HASKi^iTS. 

" We hope this excellent little work will meet with the sale its merits 
entitle it to. To every telegrapher who ownS; or uses a .Galvanometer, or 
ever expects to, it will be quite indispensable." — The Telegrapher, 



CuUey^s Hand-Book of Telegraphy. 

8vo. Cloth. $5.00. 
A HAND-BOOK OF PRACTICAL TELEGRAPHY. By 

E. S. Cl'Lley, Engineer to the Electric and International 
Telegraph Company. Fifth edition, revised and enlarged. 



Foster^s Submarine Blasting. 

4to. Cloth. '$3.50. 

SUBMAEINE BLASTING in Boston Harbor, Massachusetts— 
Eemoval of Tower and Corwin Eocks. By Johx G. Foster, 
Lieutenant-Colonel of Engineers, and Brevet Major- General, U. 
S. Army. Illustrated with seven plates. 

List of Plates. — 1. Sketch of the Narrows, Boston Harbor. 2. 
Townsend's Submarine Drilling Machine, and Working Vessel attending. 
3. Submarine Drilling Machine employed. 4. Details of Drilling Machine 
employed. 5. Cartridges and Tamping used. G. Fuses and Insulated Wireg 
used. 7. Portable Friction Battery used. 



22 SCIENTIFIC BOOKS PUBLISHED BY 

Barnes^ Submarine Warfare. 

8vo. Cloth. $5.00. 

SUBMAEINE WAEFARE, DEFENSIVE AND OFFENSIVE. 

Comprising a full and complete History of the Invention of the 
Torpedo, its employment in War and results of its use. De- 
scriptions of the yarious forms of Torpedoes, Submarine Batteries 
and Torpedo Boats actually used in War. Methods of Ignition 
by Machinery, Contact Fuzes, and Electricity, and a full account 
of experiments made to determine the Explosive Force of Gun- 
powder under "Water. Also a discussion of the Offensive Torpedo 
system, its effect upon Iron-Clad Ship systems, and influence upon 
Future Naval Wars. By Lieut. -Commander John- S. Barnes, 
U. S. N. With twenty lithographic plates and many wood-cuts. 

" A book important to military men, and especially so to engineers and ar- 
tillerists. It consists of an examination of the various offensive and defensivo 
engines that have been contrived for submarine hostilities, including a discus- 
sion of the torpedo system, its effects upon iron-clad ship-systems, and its 
probable influence upon future naval wars. Plates of a valuable character 
accompany the treatise, which affords a useful history of the momentous sub- 
ject it discusses. A great deal of useful information is collected in its pages, 
especially concerning the inventions of SCHOLL and Vehdu, and of Jones* 
and Hunt's batteries, as well as of other similar machines, and the use in 
submarine operations of gun-cotton and nitro-glycerine." — N, Y. Times, 



Randairs Quartz Operator's Hand- 

Book. 

12mo. Cloth. $2.00. 

QUAETZ OPEEATOE'S HAND-BOOK. By P. M. Ei^NDALL. 

New edition, revised and enlarged. Fully illustrated. 

The object of this work has been to present a clear and comprehensive ex- 
position of mineral veins, and the means and modes chiefly employed for the 
mining and working of their ores — more especially those containing gold and 
silver. 



D. VAIf JSrOSTUAJ^D. 23 

McOullooli's Theory of Heat. 

8vo. Cloth. In Press. 

AK ELEMENTARY TREATISE. OlST THE MECHANI- 
CAL THEORY OF HEAT, AND ITS APPLICATION 
TO AIR AND STEAM ENGINES. By Prof. R. S. Mc- 

CULLOCH. 



Benet's Ohronoscope. 

Second Edition^ 

lUnstrated. 4to. Cloth. $3.00. 

ELECTRO-BALLISTIC MACHINES, and the Schultz Ohrono- 
scope. By Lieutenant-Colonel S. V. Bei^et, Captain of Ordnance, 
U. S. Army. 

Contents.— 1. Ballistic Pendulum. 2. G-un Pendulum. 3. Use of Elec- 
tricity. 4. Navez' Machine. 5. Vignotti's Machine, with Plates. 6. Benton's 
Electro-Ballistic Pendulum, with Plates. 7. Leur's Tro-Pendulum Machine 
8. Schultz's Chronoscope, with two Plates. 



Michaeiis' Chronograph. 

4to. Illustrated. Cloth. $3.00. 

THE LE BOULENGE CHRONOGRAPH. With three litho- 
graphed folding plates of illustrations. By Brevet Captain E. 
MiCHAELis, First Lieutenant Ordnance Corps, U. S. Army. 

" The excellent monograph of Captain Michaelis enters minutely into the 
details of construction and management, and gives tables of the times of flight 
calculated upon a given fall of the chronometer for all distances. Captain 
Michaelis has done good service in presenting this work to his brother officers, 
describing, as it does, an instrument which bids fair to be in constant use in 
our future ballistic experimeniis.' — Army and Navy Journdi 



24 SCIJENTII^'IC BOOKS PUBLISHED BY 



Silversmitli's Haii(J-Book* 

Fourth Edition. 

Illustrated. 12mo. Cloth. $3.00. 

A PRACTICAL HAND-BOOK FOE MINERS, Metallurgists, 
and Assayers, comprising the most recent improvements in the 
disintegration, amalgamation, smelting, and parting of tho 
Precious Ores, with a Comprehensive Digest of the Mining 
Laws. Greatly augmented, revised, and corrected. By Julius 
Silversmith. Fourth edition. Profusdy illustrated. 1 vol. 
12mo. Cloth. $3.00. 

One of the raost important features of this work is that in which tho 
metallurgy of tho precious metals is treated of. In it the author has endeav- 
ored to embody all the processes for the reduction and manipulation of the 
precious ores heretofore successfully employed in G-ermany, England, Mexico, 
and the United States, together with such as have been more recently invented, 
and not yet fully tested — all of which are profusely illustrated and easy of 
comprehension. 



Simms' Levelling. 

8vo. Cloth. $2.50. 

A TEEATISE ON THE PEINCIPLES AND PEACTICE OF 
LEVELLING, showing its application to purposes of Pailway 
Engineering and the Construction of Poads, &c. By Frederick 
"W. SiMMs, C. E. From the fifth London edition, revised and 
corrected, with the addition of Mr. Law's Practical Examples for 
Setting Out Pailway Curves. Illustrated with three lithographic 
plates and numerous wood-cuts. 

*' One of the most imxDortant text-books for the general surveyor, and there 
is scarcely a question connected with levelling for which a solution would be 
Bought, but that would be satisfactorily answered by consulting this volume." 
— Mining Journal. 

" The text-book on levelling in most of our engineering schools and col- 
leges." — Engineers. 

"The publishers have rendered a substantial service to the profession, 
especially to the younger members, by bringing out the present edition of 
Mr. Simms' useful work." — Engineering. 



D. VAJSr JSrOSTIiAJSTD. 23 



Stnart's Successful Engineer. 

ISmo. Boards. 90 cents. 
HOW TO BECOME A SUCCESSFUL ENGINEEK: Being 
Hints to Youths intending to adopt the Profession. Bj 
Ber:n"ARD Stuaet, Engineer. Sixth Edition. 

" A valuable little book of sound, sensible advice to young men who 
wish to rise in the most important of the professions." — Scientific American. 



Stuart's Naval Dry Docks. 

Twenty-four engravings on steel. 
Fourth Edition. 

4to. Cloth. $6.00. 

THE NAVAL DRY DOCKS OF THE UNITED STATES. 

By Chaeles B. Stuaet, Engineer in Chief of the United States 

Navy. 

List of Ilhistrations, 

Pumping Engine and Pumps — Plan of Dry Dock and Pump-Well— Sec- 
tions of Dry Dock — Engine House — Iron Floating G-ate — Details of Floating 
Gate — Iron Turning Gate — Plan of Turning Gate — Culvert G-ate — Filling 
Culvert Gates — Engine Bed — Plate, Pumps, and Culvert — Engine House 
Hoof — Floating Sectional Dock — Details of Section, and Plan of Turn-Tables 
— Plan of Basin and Marine Railways — Plan of Sliding Frame, and Elevation 
of Pumps — Hydraulic Cylinder — Plan of Gearing for Pumps and End Floats 
— Perspective View of Dock, Basin, and Railway — Plan of Basin of Ports- 
mouth Dry Dock — Floating Balance Doc]^ — Elevation of Trusses and the Ma- 
chinery — Perspective View of Balance Dry Dock 



Free Hand Drawing. 

Profusely Illustrated. ISmo. Boards. 50 cents. 

A GUIDE TO OENAMENTAL, Figure, and Landscape Draw- 
ing. By an Art Student. 

Contents. — Materials employed in Drawing, and how to use them — On 
Lines and how to Draw them — On Shading— Concerning lines and shading, 
with applications of them to simple elementary subjects — Sketches from Na- 
ture. 



26 SCIENTIFIC BOOKS PUBLISHED BY ^ 

Minifie s Meeliaiiical Drawing. 

Ninth Edition, 

EoyalSvo. Cloth.- $400. 

A TEXT-BOOK OF GEOMETEICAL DRAWING- for the usp 
of Mechanics and Schools, in which the Definitions and Bules of 
Geom.etiy are famiharlj explained ; the Practical Problems are 
arranged, from the most simple to the more complex, and in their 
description technicahties are avoided as much as possible. With 
illustrations for Drawing Plans, Sections, aiid Elevations of 
Buildings and Machinery ; an Introduction to Isometrical Draw- 
ing, and an Essay on Linear Perspective and Shadows. Illus- 
trated with over 200 diagrams engraved on steel. By Wm, 
Minifie, Architect. Eighth Edition. With an Appendix on the 
Theory and Application of Colors. 

" It is the best work on Drawing that we have ever seen, and is especially a 
text-book of Geometrical Drawing for the use of Mechanics and Schools. No 
young Mechanic, such as a Machinist, Engineer, Cabinet-Maker, Millwright, 
or Carpenter, should be without it." — Scientific American. 

" One of the most comprehensive works of the kind ever published, and can- 
not but possess great value to builders. The style is at once elegant and sub- 
stantial. " — Pennsylvania Inquirer. 

" Whatever is said is rendered perfectly intelligible by remarkably well- 
executed diagrams on steel, leaving nothing for mere vague supposition ; and 
the addition of an introduction to isometrical drawing, linear perspective, and 
the projection of shadows, winding up with a useful index to technical terms.'* 
— Glasgow Mechanics' Journal. 

Kt^^ The British G-overnment has authorized the use of this book in their 
schools of art at Somerset House, London, and throughout the kingdom. 



Minifie's Geometrical Drawing. 

New Edition* Enlarged. 

12mo. Cloth. $2.00. 

GEOMETEICAL DEAWING. Abridged from the octavo edition, 
for the use of Schools. Illustrated with 48 steel plates. New 
edition, enlarged. 

*• It is well adapted as a text-book of drawing to be used in our High Schools 
and Academies where this useful branch of the fine arts has been hitherto too 
much neglected." — Boston Journal. 



D. VAN- N08T11AND. 27 

. ^ _ . 

Bell OIL Iron Smelting. 

8vo. Cloth. $6.00. 

CHEMICAL PHENOMENA OF lEON SMELTING. An ex- 
perimental and practical examination of tlie circumstances which 
determine the capacity of the Blast Eurnace, the Temperature 
of the Air, and the Proper Condition of the Materials to be 
operated upon. By I. Lowtuian Bell. 

" The reactions which take place in every foot of the blast-furnace have 
been investigated, and the nature of every step in the process, from the intro- 
duction of the raw material into the furnace to the production of the pig iron, 
has been carefully ascertained, and recorded so fully that any one in the trade 
can readily avail themselves of the knowledge acquired ; and we have no hes- 
itation in saying that the judicious application of such knowledge will do 
much to facilitate the introduction of arrangements which will still further 
economize fuel, and at the same time permit of the quality of the resulting 
metal being maintained, if not improved. The volume is one which no prac- 
tical pig iron manufacturer can afford to be without if he be desirous of en- 
tering upon that competition which nowadays is essential to progress, and 
in issuing such a work Mr. Bell has entitled himself to the best thanks of 
every member of the trade." — London Mining Journal. 



King's Notes on Steam. 

Nineteenth Edition, 

8vo. Cloth. $2.00. 

LESSONS AND PEACTICAL NOTES ON STEAM, the Steam- 
Engine, Propellers, &c., &c., for Young Engineers, Students, and 
others. By the late W. E. Kixg, U. S. N. Eevised by Chief- 
Engineer J. W. King, U. S. Navy. 

" This is one of the best, because eminently plain and practical treatises on 
the Steam Engine ever published. ' — PMladelpliia Press. 

This is the thirteenth edition of a valuable work of the late W. H. King, 
TJ. S. N. It contains lessons and practical notes on Steam and the Steam En- 
gine, Propellers, etc. It is calculated to be of great use to young marine en- 
gineers, students, and others. The text is illustrated and explained by nu- 
merous diagrams and representations of machinery.— j5(?5<c??i Daily Adver* 
User. 

Text-book at the U. S. Naval Academy, Annapoli*. 



28 SCIEJSrTIl^ia BOOKS PUBLISHED BY 

Burgh's Modern Marine Engineering. 

One thick 4to vol. Cloth. $25.00. Half morocco. $30.00. 

MODEEN MAEINE ENGINEEEING, applied to Paddle and 
Screw Propulsion. Consisting of 3G Colored Plates, 250 Practical 
Wood-cut Illustrations, and 403 pages of Descriptive Matter, the 
whole being an exposition of tho present practice of the follow- 
ing firms : Messrs. J. Penn & Sons ; Messrs. Maudslay, Sons £: 
Field ; Messrs. James Watt & Co. ; Messrs. J. & G. Ecnnio ; 
Messrs. E. Napier & Sons ; Messrs. J. & W. Dudgeon ; Messrs. 
Eavenhill & Hodgson ; Messrs. Humphreys & Tenant ; Mr. 
J. T. Spencer, and Messrs. Forrester & Co. By N. P. BuEGn, 
Engineer. 

Principal Contents. — General Arrangements of Engines, 11 examples 
— General Arrangement of Boilers, 14 examples — General Arrangement of 
Superheaters, 11 examples — Details of Oscillating Paddle Engines, o4 ex- 
amples — Condensers for Screw Engines, both Injection and Surface, 20 ex- 
amples — Details of Screw Engines, 20 examples — Cylinders and Details of 
Screw Engines, 21 examples — Slide Valves and Details, 7 examples — Slide 
Valve, Link Motion, 7 examples — Expansion Valves and Gear, 10 exam- 
ples — Details in General, 80 examples — Screw Propeller and Fittings, 13 ex- 
amples-Engine and Boiler Fittings, 28 examples -In relation to the Princi- 
ples of the Marine Engine and Boiler, 33 examples. 

Notices of the Press. 

"Every conceivable detail of the Marine Engine, under all its various 
forms, is profusely, and we must add, admirably illustrated by a multitudo 
of engravings, selected from the best and most modern practice of the first 
Marine Engineers of the day. The chapter on Condensers is peculiarly valu- 
able. In one word, there is no other work in existence which will bear a 
moment's comparison with it as an exponent of the skill, talent and i^ractical 
experience to which is due the splendid reputation enjoyed by many British 
Marine 'EnginQQi^y — Engineer. 

" This very comprehensive work, which was issued in Monthly parts, has 
just been completed. It contains large and full drawings and copious dc- 
Bcriptiona of most of the best examples of Modern Marine Engines, and it is 
a complete theoretical and practical treatise on the subject of Marine Engi- 
neering." — Americcin Artisan. 

This is the only edition of tho above work with the beautifully colored 
plates, and it is out of print in England. 



D. VAN NOSTRAND, 2S 



Bourne's Treatise on the Steam En^ 

gine. 

Ninth Edition* 

Illustrated. 4to. Gloth. $15.00. 
TEEATISE ON THE STEAM ENGINE in its various appUca. 
tions to Mines, MiUs, Steam Navigation, Bailways, and AgricuL 
ture, with, the theoretical investigations respecting the Motive 
Power of Heat and the proper Proportions of Steam Engines. 
Elaborate Tables of the right dimensions of every part, and 
Practical Instructions for the Manufacture and Management of 
every species of Engine in actual use. By Joui?" Boitene, being 
the ninth edition of *' A Treatise on the Steam Engine,^' by 
the *^ Artisan Club." Illustrated by thirty-eight plates and five 
hundred and forty-six wood-cuts. 

As Mr. Bourne's work has the great merit of avoiding unsound and imma- 
ture views, it may safely be consulted by all who are really desirous of ac- 
quiring trustworthy information on the subject of which it treats. During 
the twenty-two years which have elapsed from the issue of the first edition, 
the improvements introduced in the construction of the steam engine have 
been both numerous and important, and of these Mr. Bourne has taken caro 
to point out tUQ more prominent, and to furnish the reader with such infor- 
mation as shall enable him readily to judge of their relative value. This edi- 
tion has been thoroughly modernized, and made to accord with the opinions 
and practice of the more successful engineers of the present day. All that 
the book professes to give is given with ability and evident care. The scien- 
tific principles which are permanent are admirably explained, and reference 
is made to many of the more valuable of the recently introduced engines. To 
express an opinion of the value and utility of such a work as The Artisan 
duo's Treatise on the Steam Engine, which has passed through eight editions 
already, would be superfluous ; but it may be safely stated that the work is 
worthy the attentive study of all either engaged in the manufacture of steam 
engines or interested in economizing the use of steam. — Mining Journal, 



Isherwood's Engineering Precedents. 

Two Vols, in One. 8vo. Cloth. $2.50. 

ENGUVTEEEING PEECEDENTS EOE, STEAM MACHINEET. 

Arranged in the most practical and useful manner for Engineers. 
By B. F. IsHEEWooD, Civil Engineer, U. S. Navy. With illus- 
trations. 



30 SCIEN'TIFIC BOOKS PUBLISHED BY 



"Ward's Steam for the Million. 

^ew and Ilevlsed Edition^ 

8vo. Cloth. §1.00. 

STEAM FOE THE MILLION. A Poi^ular Treatise on Steam 
and its Application to the Useful Arts, especially to Naviga- 
tion. By J. H. Waed, Commander U. S. Navy. New and re- 
vised edition. 

A most excellent work for the young engineer and general reader. Many 
facts relating to the management of the boiler and engine are sot forth with a 
simplicity of language and perfection of detail that bring the subject home 
to the reader. — American Engineer. 



Walker's Botqvt Propulsion. 

8vo. Cloth. 75 cents. 

NOTES ON SCREW PEOPULSION, its Eise and History. By 
Capt. W. H. Walker, U. S. Navy. 

Commander "Walker's book contains an immense amount of concise practi- 
cal data, and every item of information recorded fully proves that the various 
points bearing upon it have been well considered previously to expreeskig an 
opinion. — London Mning Journal. 



Page's Earth's Crust. 

18mo. Cloth. 75 cents. 

THE EAETH'S CEUST ; a Handy Outline of Geology. By 
David Page. 

" Such a work as this was much wanted — a work giving in clear and intel- 
ligible outline tho leading facts of the science, without amplification or irk- 
some details. It is admirable in arrangement, and clear and easy, and, at tho 
same time, forcible in style. It will lead, wo liope., to tho introduction of 
Geology into many schools that have neither time nor room for tho study of 
lararo treatises." — TJie jSiuseum. 



D. VAN N'OSTllAJSrif. 31 

"^ » 

» ■ ' — ' 

Rogers' Geology of Pennsylvania. 

3 Vols. 4to, with Portfolio of Maps. Clotli. $30.00. 

THE GEOLOGY OF PENNSYLVANIA. A Govemment Sur- 
vey. With, a general view of the Geology of the United States, 
Essays on the Coal Formation and its Fossils, and a description 
of the Coal Shields of North America and Great Britain. By 
Henry Dakwin Eogers, Late State Geologist of Pennsylvania. 
Splendidly illustrated with Plates and Engravings in tlie Text. 

It certainly should be in every public library throughout the country, and 
likewise in the possession of all students of G-eology. After the final sale of 
these copies, the work Viil, of course, become more valuable. 

The work for the last five years has been entirely out of the market, hut a 
few copies that remained in the hands of Prof. Rogers, in Scotland, at the 
time of his death, are now offered to the public, at a price which is even 
below what it was originally sold for when first published. 



Morfit on Pure Fertilizers. 

With 28 Illustrative Plates. 8vo. Cloth. $20.00. 

A PEACTICAL TEEATISE ON PUEE FEETILIZEES, and 

the Chemical Conversion of Eock Guanos, Maiilstones, Coproliteib, 
and the Crude Phosphates of Lime and Alumina Generally, into 
various Valuable Products. By Campbell Moefit, M.D., E.C.S. 



Sweet^s Report on Coal. 

8vo. Cloth. $3.00. 

SPECIAL EEPOET ON COAL ; showing its Distribution, Classi- 
fication, and Cost delivered over different routes to various points 
in the State of New York, and the principal cities on the Atlantic 
Coast. By S. H. Sweet. With maps. 



Oolbnrn^s Gas Works of London, 

13ino. Boards. 60 cents. 
GAS WORKS OF LONDON. By Zekah Colbukn. 



32 SCIENTIFIC BOOKS PUBLISHED BY 

The Useful Metals and tlieir Alloys ; 
Scofiren, Truran, and others. 

FiSth Edition. 

8vo. Hatfcalf. $3.75. 

THE USEFUL METALS AND THEIE ALLOYS, including 
MINING VENTILATION, MINING JUEISPEUDENCE 
AND METALLUEGIO CHEMISTEY employed in the conver- 
sion of lEON, COPPEE, TIN, ZINC, ANTIMONY, AND 
LEAD OEES, with their applications to THE INDUSTEIAL 
AETS. By John ScorpiiEN, "William Texjran, William Clay, 
EoBEET OxLAND, WiLLiAM Eaieb.viex, W. C. Aitkin, and Wil- 
liam VosE Pickett. 



Collins' Useful Alloys. 

18mo. Flexible. 75 cents. 

THE PEIVATE BOOK OF USEFUL ALLOYS and Memo- 
randa for Goldsmiths, Jewellers, etc. By James E. Collins 

This little book is compiled from notes made by the Author from the 
papers of one of the largest and most eminent Manufacturing Goldsmiths and 
Jewellers in this country, and as the firm is now no longer in existence, and the 
Author is at present engaged in some other undertaking, he now offers to the 
public the benefit of his experience, and in so doing he begs to state that all 
the alloys, etc., given in these pages may be confidently relied on as being 
thoroughly practicable. 

The Memoranda and Keceipts throughout this book are also compiled 
from practice, and will no doubt be found useful to the practical jeweller. 
— Shirley J July, 1871. 

Joynson's Metals Used in Construction. 

12mo. Cloth. 75 cents. 

THE METALS USED IN CONSTEUCTION : Iron, Steel, 
Bessemer Metal, eto., etc. By Francis Herbert Joynson. Il- 
lustrated. 

" In the interests of practical science, we are bound to notice this work ; 
and to those who wish further information, we should say, buy it ; and the 
outlay, ^yQ honestly believe, will be considered well spent." — Scientific 
Review. 



D. VAN NOSTRAND. S3 

Prescott's Proximate Organic 
Analysis. 

12mo. Cloth, $1.75. 
OUTLINES OF PROXIMATE OEOANIC A^fALYSIS 
for the Identification^, Separation, and Quantitative Deter- 
mination of the more commonly occurring Organic Com- 
pounds. By Albert B. Peescott, Professor of Organic 
and Applied Chemistry in the Uniyersity of Michigan. 



Prescott's Alcoholic Liquors. 

12mo. Cloth. $1.50. 
CHEMICAL EXAMINATION OF ALCOHOLIC LI- 
QUORS. A Manual of the Constituents of the Distilled 
Spirits and Fermented Liquors of Commerce^ and their 
Qualitative and Quantitative Determinations. By Albert 
B. Prescott^ Professor of Organic and Applied Chemistry 
in the University of Michigan. 



Greene's Bridge Trnsses. 

8vo. Illustrated. Cloth. |2.00. 
GRAPHICAL METHOD FOR THE ANALYSTS OF 
BRIDGE TRUSSES, extended to Continuous Girders 
and Draw Spans. By Charles E. Gree:n'e, A.M., Pro- 
fessor of Civil Engineering, University of Michigan. Illus- 
trated by three folding plates. 



Butler's Projectiles and Rifled Cannon. 

4to. 86 Plates, Cloth. $7.50. 

PROJECTILES AND RIFLED CANNON. A Critical Dis- 
cussion of the Principal Systems of Rifling and Projectiles, 
with practical suggestions for their improvement, as embraced 
in a report to the Chief of Ordnance, U. S. Army, By Capt. 
Joh:n" S. Butler, Ordnance Corps, U. S. A. 



34 SCIENTIFIC BOCKS PUBLISHED BY 

Peiree's Anal3rtic Mechanics. 

4to. Cloth. $10.00. 

SYSTEM OF ANALYTIC MECHANICS. Physical and Celestial 
Mechanics. By Benjamik Peirce, Perkins Professor of Astronomy 
and Mathematics in Harvard University, and Consulting As- 
tronomer of the American Eph.emeris and Nautical Almanac. 
Developed in four systems of Analytic Mechanics, Celestial 
Mechanics, Potential Physics, and Analytic Morphology. 

*' I have re-examined the memoirs of the great geometers, and have striven 
to consolidate their latest researches and their most exalted forms of thought 
into a consistent and uniform treatise. If I have hereby succeeded in open- 
ing to the students of my country a readier access to these choice jewels of 
intellect ; if their brilliancy is not impaired in this attempt to reset them ; if, 
in their own constellation, they illustrate each other, and concentrate 
a stronger light upon the names of their discoverers , and, still more, if any 
gem which I may have presumed to add is not wholly lustreless in the coUcc" 
tion, I shall feel that my work has not been in vain." — Extract from the Pre^ 
face, 

Burt's Key to Solar Compass. 

Second Edition, 

Pocket Book Eorm. Tuck. $2.50. 

KEY TO THE SOLAE COMPASS, and Surveyor's Companion ; 
comprising all the Eules necessary for use in the field; also, 
Description of the Linear Surveys and Public Land System of 
the United States, Notes on the Barometer, Suggestions for an 
outfit for a Survey of four months, etc., etc., etc. By W. A. 
BuET, U. S. Deputy Surveyor. Second edition. 



Ohaiiveiiet's Lunar Distances. 

8vo. Cloth. $3.00. 

NEW METHOD OF COEREOTING LUNAR DISTANCES, 
and Improved Method of Finding the Error and Rate of a Chro- 
nometer, by equal altitudes. By Wm. Chauvenet, LL.D., Chan- 
cellor of Washington University of St. Louis. 



D. VAN NOSTRAND. 35 



Jefiers' Nautical Surveying. 

Illustrated with. 9 Copperplates and 31 "WcK)d-ciit Illustrations. 8vo, 

Cloth. $5.00. 

NAUTICAL SUEYEYING. By William N. Jeffees, Captain 
U. S, Navy. 

Many books have been written on each of the subjects treated of in the 
sixteen chapters of this work; and, to obtain a complete knowledge of 
geodetic surveying requires a profound study of the whole range of matbe- 
inatical and physical sciences ; but a year of preparation should render any 
intelligent ofScer competent to conduct a nautical survey. 

Contents. — Chapter I. Formulae and Const&,nts Useful in Surveying 
II. Distinctive Character of Surveys. III. Hydrographic Surveying under 
Sail ; or, Kunning Survey. IV. Hydrograpbic Surveying of Boats ; or, Har- 
bor Survey. V. Tides — Definition of Tidal Phenomena — Tidal Observations. 
VI. Measurement of Bases — Appropriate and Direct. VII. Measurement of 
the Angles of Triangles — Azimuths — Astronomical Bearings. VIII. Correc- 
tions to be Applied to the Observed Angles. IX. Levelling — Difference of 
Level. Z. Computation of the Sides of the Triangulation — The Three-point 
Problem. XI. Determination of tbe G-eodetic Latitudes, Longitudes, and 
Azimuths, of Points of a Triangulation. XII. Summary of Subjects treated 
of in preceding Chapters — Examples of Computation by various Formulse. 
XIII. Projection of Charts and Plans. XIV. Astronomical Determination of 
Latitude and Longitude. XV. Magnetic Observations. XVI. Deep Sea 
Soundings. XVII. Tables for Ascertaining Distances at Sea, and a full 
Index. 

List of Plates, 

Plate I. Diagram Illustrative of the Triangulation. II. Specimen Page 
of Field Book. III. E-unning Survey of c Coast. IV. Example of a Running 
Survey from Belcher. V. Flying Survey of an Island. VI. Survey of a 
Shoal. VII. Boat Survey of a River. VIII. Three-Point Problem. IX. 
Triangulation. 



Cof&n's Navigation. 

Fifth Edition, 

12mo. Cloth. $3.50. 

NAVIGATION AND NAUTICAL ASTEONOMY. Prepared 

for the use of the U. S. Naval Academy. By J. H. C. Coffin, 
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36 SCIENTIFIC BOOK^ PUBLISHED BY 

Clark's Theoretical INTavigatioii. 

8vo. Cloth. $3.00. 

CHEOEETICAL NAVIGATION AND NAUTICAL ASTEON- 
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The Plane Table. 

Illustrated. 8yo. Cloth. $2.00. 

tTS USES IN TOPOGEAPHICAL SURVEYING. Erom the 
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This work gives a description of the Plane Table employed at the U. S. 
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Pook on Shipbuilding. 

8vo. Cloth. $5.00. 

METHOD OF COMPARING THE LINES AND DRAUGHT- 
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Brunnow's Spherical Astronomy. 

8vo. Cloth. $6.50. 

SPHERICAL ASTRONOMY. By F. Brunnow, Ph. Dr. Trans- 
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IK VAJSr mjSTF.AND, 37 

Van Bnren's Formulas. 

8vo. Cloth. $2.00. 

INVESTIGATIONS OF FOEMIILAS, for the Strengtli of the 
Iron Parts of Steam Machinery. By J. D. Yan Btjeex, Jr., C E. 
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This is an analytical discussion of the formulas employed by mechanical 
engineers in determining the rupturing or cripphng pressure in the different 
parts of a machine. The formulae are founded upon the principle, that the 
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Joynson on Macliiiie Gearing. 

8vo. Cloth. $2.00. 

THE MECHANIC'S AND STUDENT'S GUIDE in the Design- 
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Barnard's Report, Paris Exposition, 

1867. 

Illustrated. 8vo. Cloth. $5.00. 

EEPOET on MACHINERY AND PEOCESSES ON THE 
INDUSTRIAL AETS AND APPAEATUS OF THE EXACT 
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Exposition, 1867. 

"We have in this volume the results of Dr. Barnard's study of the Paris 
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38 SCIENTIFIC BOOKS PUBLISHED BT 

Engineering Facts and Figures. 

18mo. Clotli. $3.50 per Volume. 

AN ANNUAL REGISTER OF PROGRESS IN MECHANI- 
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Beckwith's Pottery. 

8vo. Paper. 60 cents. 

OBSEEVATIONS ON THE MATEEIALS and Manufacture of 
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" Everything is noticed in this book which comes under the head of Pot- 
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Dodd^s Dictionary of Manufactures, etc. 

IkiiiLo. Cioch. $2.00. 

DICTIONAEY OF MANUFACTURES, MURING, MACHIN- 
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D. VAJSl NOBTRAND. 39 

Stuart's Oivil and Military Engineer- 
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8vo. Illustrated. Cloth. $5.00. 

THE CIVIL AND MILITAEY ENGINEEES OF AMEEICA. 
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by engravings of some of the most important and original works 
constructed in America. 

Containing sketches of the Life and "Works of Major Andrew Ellicott, 
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trait), Jonathan Knight, Benjamin H. Latrobe (with Portrait), Colonel Char- 
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Alexander's Dictionary of Weights 
and Measures. 

8vo. Cloth. $3.50. 

UNIVEESAL DICTIONAEY OP WEIGHTS AND MEAS- 
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Blake's Ceramic Art. 

8vo. Cloth. $3.00. 

A REPORT 0?f POTTERY, PORCELAUST, TILES, TERRA- 
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40 SCIENTIFIC BOOKS PUBLISHED BY 

Saeltzer's Aconstics. 

12mo. Cloth. $2.00. 

TEEATISE ON ACOUSTICS in Connection with Ventilation. 
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" A practical and very sound treatise on a subject of great importance to 
architects, and one to -which there has hitherto been entirly too little attention 
paid. The author's theory is, that, by bestowing proper care upon the point 
of Acoustics, the requisite ventilation will be obtained, and mcQ versa, — 
Brooklyn Union. 



Myer's Manual of Signals. 

New Edition. Enlarged. 

12mo. 48 Plates full Koan. $5.00. 

MANUAL OF SIGNALS, for the Use of Signal Officers in the 
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the Signal Corps during the War of the Rebellion. 



Larrabee's Secret Letter and 
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18mo. Cloth. $1.00. 

CIPHEE AND SECRET LETTER AND TELEGRAPHIC 
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By C. S. Larrabee, the original inventor of the scheme. 



D. VAN NOSTRAND. 41 

/ ' ... ' 

Hunt's Designs for Central Park 
Gate^^ays, 

4to. Cloth. $5.00. 

DESIGNS rOE THE GATEWAYS OE THE SOUTHEEN 
ENTEANCES TO THE CENTEAL PAEK. Bj Eichakd M. 
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Pickert and Metcalf's Art of Graining. 

1 Yol. 4to. Cloth. $10.00. 

THE AET OF GEAINING. How Acquired and How Produced, 
with description of colors and their appHcation. By Charles 
Pickert and Abrahaii Metcalf. Beautifully illustrated with 42 
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Tinted paper. 

The authors present here the result of long experience in the practice of 
this decorative art, and feel confident that they hereby offer to their brother 
artisans a reliable guide to improvement in the practice of graining. 



Portrait Gallery of the War. 

60 fine Portraits on Steel. Hoyal 8vo. Cloth. $6.00. 

POETEAIT GALLEEY OF THE WAE, CIVIL, MILITAEY 
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One Law in Nature • 

12mo. Cloth. $1.50. 

ONE LAW IN NATUEE. By Capt. H. M. Lazelle, U. S. A. 
A New Corpuscular Theory, comprehending Unity of Eorce, 
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42 SCIENTIFIC B OKS I UBLISIIED B Y 

Ernst's Manual of Military En- 
gineering. 

193 Wood Cuts and G Lithographed Plates. 12mo. Cloth. $5.00. 

A MANUAL OF PRACTICAL MILITAKY ENGINEER- 
INGr. Prepared for the nse^f the Cadets of the U. S. Military 
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neering, U. S. Military Academy. 



' Oliurcli's Metallurgical Journey. 

24 Illustrations. 8vo. Cloth. $2.00. 

NOTES OP A METALLURGICAL JOURNEY IN' 
EUROPE. By Johk A. Church, Engineer of Mines. 



Blake's Precious Metals. 

8vo. Cloth. $2.00. 
REPORT UPON THE PRECIOUS METALS : Being Statisti- 
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of the World. Represented at the Paris Universal Exposi- 
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of California. 



Olevenger's Surveying. 

Illustrated Pocket Form. Morocco Gilt. $2.50. 

A TREATISE ON THE METHOD OP GOVERNMENT 
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Students who contemplate engaging in the business of Public 
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" The reputation of the author as a surveyor guarantees an exhaustive 
treatise on this subject." — Dakota Register, 

*' Purveyors have long needed a text-book of this description. — Tlia Press, 



D. VAN NO STRAND, 43 

Bow on Bracing. 

156 Illustrations on Stone. 8vo. Cloth. $1.50. 

A TKEATISB 0]\" BKACITsT G, with its upplicatioii to Bridges 
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Howard's Earthwork Mensuration. 

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EARTHWORK MENSURATION ON THE BASIS OF 
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panied by Plain Rules for practical uses. By CoisrwAY R, 
Howard, Civil Engineer, Richmond, Va. 



"Major Howard has given in this book a simple, yet perfectly accurate 
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has all the accuracy of the prisrnoidal formula with scarcely more trouble than 
in averaging end areas. 

H. D. WHITCOMB, 

Chief Engineer Chesapeake and Ohio E. E. 

E. T. D. MYERS, 

Chief Engineer Eichmond^ Fredericksburg^ and Potomac E. J?." 



Mowbray's Tri-Nitro-Qlycerine. 

8vo. Cloth. Illustrated. |3.00. 

TRI-NITRO-GLYCERINE, as applied in the Iloosac Tunnel, 
and to Submarine Blasting, Torpedoes, Quarrying, etc. Being 
tlie result of six years' observation and practice during the 
manufacture of five hundred thousand pounds of this explo- 
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U S CIENTIFIC B OKS P U BLUSHED B Y 



the various Systems of Blasting by Electricity, Priming Com- 
pounds, Explosives, etc., etc. By George M. Mowbray, 
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appendix. Third Edition. Ee-written. 



Wanklyn's Milk Analysis. 

12mo. Cloth. $1.00. 

MILK ANALYSIS. A Practical Treatise on the Examination 
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J. Alfred WAKKLY^ir, M. E. C. S. 



Toner^s Dictionary of Elevations. 

8vo. Paper, $3.00. Clotli, $3.75. 

DICl^IONAEY OP ELEVATIONS AND CLIMATIC REG- 
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brief Introduction on the Orographic and Physical Peculiari- 
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Adams. Sewers and Drains. 

(In Press) 

SEWERS AND DRAINS FOR POPULOUS DISTRICTS, 

Embracing Rules and Formulas for the Dimensions and Con- 
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i). VAN NOSTRAND. ^^ 



SILYEE MINING REGIONS OF COLORADO, with some* 
account of the different Processes now being introduced for 
working the Gold Ores of that Territory. By J. P. Whitney.. 
12mo. Paper. 25 cents. 



COLORADO : SCHEDULE OF ORES contributed by sundry 
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information about the Region and its Resources. By J. P. 
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THE SILVER DISTRICTS OF NEVADA. With Map. 8yo. 
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ARIZONA : ITS RESOURCES AND PROSPECTS. By Hon. 
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MONTANA AS IT IS. Being a general description of its Re- 
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description of the face of the country, its climate, etc. Illustrated 
with a Map of the Territory, showing the different Roads and 
the location of the different Mining Districts. To which is 
appended a complete Dictionary of The Snake Language, and 
also of the famous Chinnook Jargon, with numerous critical and 
explanatory Notes. By Geanyille Stuabx. Svo. Paper. $2.00, 



RAILWAY GAUGES. A Review of the Theory of Narrow 
Gauges as applied to Main Trunk Lines of Railway. By Silas 
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REPORT made to the President and Executive Board of the 
Texas Pacific Railroad. By Gen. G. P. Buell, Chief Engineer. 
Svo. Paper. 75 cents. 



46 SCIENCi: SERIES PUBLISHED BY 



Van Nostrand's Science Series. 



It is the intention of the Publisher of this Series to issue them at inter- 
vals of about a month. They will be put up in a uniform, neat and attrac- 
tive form, 18mo, fancy boards. The subjects will be of an eminently 
scientific character, and embrace as wide a range of topics as possible, all 
of the highest character. 

Price, 50 Cents Each. 
1. 

CHIMNEYS FOR FURNACES, FIRE-PLACES, AND 
STEAM BOILERS. By R. Aemsteokg, C. E. 

STEAM BOILER EXPLOSIONS. By Zekah Colburi^. 

PRACTICAL DESIGNING OF RETAINING WALLS 
By Arthur Jacob, A. B. With Illustrations. 

4- 

PROPORTIONS OF PINS USED IN BRIDGES. By 
Charles E. Bekder, C. E. With. Illustrations. 

5. 

VENTILATION OF BUILDINGS. By W. F. Butler. With 
Illustrations. 

6. 

ON THE DESIGNING AND CONSTRUCTION OF STOR- 
AGE RESERVOIRS. By Arthur Jacob. With Illustra- 
tions. 

SURCHARGED AND DIFFERENT FORMS OF RETAIN- 
ING WALLS. By James S. Tate, C. E. 

8. 

A TREATISE ON THE COMPOUND ENGINE. By John 

TuRNBULL. With Illustrations. 

e. 

FUEL. By C. W. Siemens to which is appended the Value of 
Artificial Fuels as compared with Coal. By J. Wormald, C. E. 

lO. 
COMPOUND ENGINES. Translated from the French of 
A. Mallet. Illustrated. 



D. VAN NOSTRAND. 47 



11. 
THEORY OF ARCHES. By Prof. W. Allan, of the 
Washington and Lee "College. Illustrated. 

12. 
A PRACTICAL THEORY OF VOUSSOIR ARCHES. By 
William Cain, C.E. Illustrated. 

13. 
A PRACTICAL TREATISE ON THE GASES MET 
WITH IN COAL-MINES. By the late J. J. Atkinson, 
GoYernment Inspector of Mines for the County of Durham, 
England. 

14. 

FRICTION OF AIR IN MINES. By J. J. Atkinson, 
author of ^^ A Practical Treatise on the Gases met with in 
Coal-Mines." 

15. 

SKEW ARCHES. By Prof. E. W. Hyde, C.E. Illustrated 
with numerous engravings and three folded plates. 

16. 
A GRAPHIC METHOD FOR SOLVING CERTAIN AL- 
GEBRAIC EQUATIONS. By Prof. George L. Vose. 
With illustrations. 

17. 
WATER AND WATER SUPPLY. By Prof. W. H. Cor- 
FiELD, M.A., of the University College, London. 

18. 
SEWERAGE AND SEWAGE UTILIZATION. By Prof. 
W. H. CoRFiELD, M.A., of the University College, London. 

19. 
STRENGTH OF BEAMS UNDER TRANSVERSE 
LOADS. By Prof . W. Allan, author of ^^ Theory of 
Arches." With illustrations. 



Author ..kZQIl^^^.jjAj^jA^iJk-Ju^^jL. 

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